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Here you can find recent articles from Nature, Acta Materialia, Scripta Materialia, Computational Materials Science, Physical Review Letter, Physical Review B, Journal of Physics: Condensed Matter and Science and Engineering A. If you have more suggestions, feel free to write me!

July 20 2020

Electrical Probes of the Non-Abelian Spin Liquid in Kitaev Materials

David Aasen, Roger S. K. Mong, Benjamin M. Hunt, David Mandrus, and Jason Alicea

Tailored circuits joined to a quantum spin liquid provide a way to electrically probe the spin liquid’s fractionalized excitations, a key step toward harnessing such systems for fault-tolerant quantum computing.

Physical Review X

Distinct Topological Surface States on the Two Terminations of ${\mathrm{MnBi}}_{4}{\mathrm{Te}}_{7}$

Xuefeng Wu, Jiayu Li, Xiao-Ming Ma, Yu Zhang, Yuntian Liu, Chun-Sheng Zhou, Jifeng Shao, Qiaoming Wang, Yu-Jie Hao, Yue Feng, Eike F. Schwier, Shiv Kumar, Hongyi Sun, Pengfei Liu, Kenya Shimada, Koji Miyamoto, Taichi Okuda, Kedong Wang, Maohai Xie, Chaoyu Chen, Qihang Liu, Chang Liu, and Yue Zhao

Experiments reveal that unusual surface behavior at the terminations of a recently discovered magnetic topological insulator depends on the interplay between different building blocks within the material.

Physical Review X

Dynamics of Many-Body Photon Bound States in Chiral Waveguide QED

Sahand Mahmoodian, Giuseppe Calajó, Darrick E. Chang, Klemens Hammerer, and Anders S. Sørensen

A proposed optical waveguide would take a light pulse and break it into sets of strongly correlated photons, which may give a leg up to certain quantum technologies.

Physical Review X

Hierarchy of Linear Light Cones with Long-Range Interactions

Minh C. Tran, Chi-Fang Chen, Adam Ehrenberg, Andrew Y. Guo, Abhinav Deshpande, Yifan Hong, Zhe-Xuan Gong, Alexey V. Gorshkov, and Andrew Lucas

Quantum systems with certain long-range interactions exhibit a hierarchy of limits on information transfer rates—a set of nested “light cones”—that set fundamental restrictions for a range of quantum-based technologies.

Physical Review X

Electron-Hole Interference in an Inverted-Band Semiconductor Bilayer

Matija Karalic, Antonio Štrkalj, Michele Masseroni, Wei Chen, Christopher Mittag, Thomas Tschirky, Werner Wegscheider, Thomas Ihn, Klaus Ensslin, and Oded Zilberberg

Coupled semiconductor layers of InAs and GaSb can be used to realize a Fabry-Pérot interferometer in which electrons and holes incident at all angles lead to an interference pattern.

Physical Review X

Superfluid Flow of Polaron Polaritons above Landau’s Critical Velocity

K. Knakkergaard Nielsen, A. Camacho-Guardian, G. M. Bruun, and T. Pohl

We develop a theory for the interaction of light with superfluid optical media, describing the motion of quantum impurities that are created and dragged through the liquid by propagating photons. It is well known that a mobile impurity suffers dissipation due to phonon emission as soon as it moves f...

Physical Review Letters

Metadynamics of Paths

Davide Mandelli, Barak Hirshberg, and Michele Parrinello

We present a method to sample reactive pathways via biased molecular dynamics simulations in trajectory space. We show that the use of enhanced sampling techniques enables unconstrained exploration of multiple reaction routes. Time correlation functions are conveniently computed via reweighted avera...

Physical Review Letters

Multiple-photon transitions in electrically detected magnetic resonance measurements of $4H\text{−}\mathrm{SiC}$ transistors

James P. Ashton and Patrick M. Lenahan

We report an ultralow-field frequency-swept electrically detected magnetic resonance (fsEDMR) measurement scheme sensitive to so-called ultrastrong coupling in paramagnetic systems, which arises from comparatively strong driving fields and weak Zeeman interaction with small static fields. We observe...

Physical Review B Structure, Structural phase transitions, Mechanical properties, Defects

Phonon structure of titanium under shear deformation along ${10\overline{1}2}$ twinning mode

Atsushi Togo, Yuta Inoue, and Isao Tanaka

We investigated phonon behavior of hexagonal close-packed titanium under homogeneous shear deformation corresponding to the ${10\overline{1}2}$ twinning mode using first-principles calculations and phonon calculations. By this deformation, we found that a phonon mode located at a point on the Brillo...

Physical Review B Structure, Structural phase transitions, Mechanical properties, Defects

Order-parameter coupling and strain relaxation behavior of ${\mathrm{Ti}}_{50}{\mathrm{Pd}}_{50−x}{\mathrm{Cr}}_{x}$ martensites

S. L. Driver, E. K. H. Salje, C. J. Howard, G. I. Lampronti, X. Ding, and M. A. Carpenter

A group theoretical model is proposed for linear/quadratic coupling between order parameters which arise from electronic and soft-mode instabilities in doped shape memory alloys, together with coupling to symmetry breaking shear strains. This model is tested by using resonant ultrasound spectroscopy...

Physical Review B Structure, Structural phase transitions, Mechanical properties, Defects

Concurrent phase retrieval for imaging strain in nanocrystals

Marcus C. Newton

Coherent diffraction imaging is a form of microscopy that permits high resolution imaging of atomic displacements from equilibrium where the use of conventional optics is not feasible. Approaches to date for the recovery of atomic displacements from equilibrium and subsequently strain information oc...

Physical Review B Structure, Structural phase transitions, Mechanical properties, Defects

High-precision equation of state data for ${\mathrm{TiO}}_{2}$: A structural analog of ${\mathrm{SiO}}_{2}$

Sakun Duwal, Chad A. McCoy, Philippe F. Weck, Patricia Kalita, Heath L. Hanshaw, Kyle Cochrane, Tommy Ao, and Seth Root

The high-pressure response of titanium dioxide (${\mathrm{TiO}}_{2}$) is of interest because of its numerous industrial applications and its structural similarities to silica (${\mathrm{SiO}}_{2}$). We used three platforms—Sandia's Z machine, Omega Laser Facility, and density-functional theory-based...

Physical Review B Structure, Structural phase transitions, Mechanical properties, Defects

Chemical ordering and pressure-induced isostructural and electronic transitions in MoSSe crystal

Achintya Bera, Anjali Singh, Y. A. Sorb, Ramesh Naidu Jenjeti, D. V. S. Muthu, S. Sampath, Chandrabhas Narayana, U. V. Waghmare, and A. K. Sood

Isostructural transitions in layered $M{X}_{2}$ compounds are governed by competing van der Waals (vdW) and Coulomb interactions. While an isostructural transition (at $P∼$ 20 GPa) has been observed before metallization in ${\mathrm{MoS}}_{2}$ when subjected to pressure, it is surprisingly missing i...

Physical Review B Structure, Structural phase transitions, Mechanical properties, Defects

Manifestation of structural Higgs and Goldstone modes in the hexagonal manganites

Quintin N. Meier, Adrien Stucky, Jeremie Teyssier, Sinéad M. Griffin, Dirk van der Marel, and Nicola A. Spaldin

Spontaneous breaking of a continuous symmetry described by a Mexican hat potential is relevant in many areas of physics, from magnetism to particle physics. Its effects manifest in the excitation spectrum as the emergence of Higgs and Goldstone modes, which are the amplitude and phase fluctuations of the order parameter. Here, the authors show, using density functional and Landau theories and Raman spectroscopy, that phonons at the crystallographic phase transition in the multiferroic hexagonal manganites provide a manifestation of Higgs and Goldstone excitations.

Physical Review B Structure, Structural phase transitions, Mechanical properties, Defects

Atomic cluster expansion of scalar, vectorial, and tensorial properties including magnetism and charge transfer

Ralf Drautz

The atomic cluster expansion [R. Drautz, Phys. Rev. B 99, 014104 (2019)] is extended in two ways, the modeling of vectorial and tensorial atomic properties and the inclusion of atomic degrees of freedom in addition to the positions of the atoms. In particular, atomic species, magnetic moments, and c...

Physical Review B Structure, Structural phase transitions, Mechanical properties, Defects

A model and simulation of lattice vibrations in a superabundant vacancy phase of palladium–deuterium

M R Staker

A one dimensional Bravais lattice model is applied to a superabundant vacancy (SAV) delta δ phase (Pd 3 VacD 4 —octahedral), in the palladium–deuterium system. SolidWorks is used to simulate the motion of atoms and ions in the lattice. These two approaches give identical results for the vibrations of the deuterons indicating that large vibrations of deuterons are possible when the microstructure is a mixture of beta deuteride and small volume percent delta SAV phase. These conditions result from the unique geometry and crystallography of δ phase. According to both the model and simulation, as the size of δ phase increases, opportunity for high amplitude vibrations of deuterons increases. Increasing temperature should have a similar effect.

Modelling and Simulation in Materials Science and Engineering

Simulation of capillary-driven kinetics with multi-phase-field and lattice Boltzmann method

Raphael Schiedung, Marvin Tegeler, Dmitry Medvedev and Fathollah Varnik

We propose a combined computational approach based on the multi-phase-field and the lattice Boltzmann method for the motion of solid particles under the action of capillary forces. The accuracy of the method is analyzed by comparison with the analytic solutions for the motion of two parallel plates of finite extension connected by a capillary bridge. The method is then used to investigate the dynamics of multiple spherical solid bodies connected via capillary bridges. The amount of liquid connecting the spheres is varied, and the influence of the resulting liquid-morphology on their dynamics is investigated. It is shown that the method is suitable for a study of liquid-phase sintering which includes both phase transformation and capillary driven rigid body motion.

Modelling and Simulation in Materials Science and Engineering

Topology of SiO x -units and glassy network of magnesium silicate glass under densification: correlation between radial distribution function and bond angle distribution

Nguyen Hung Son, Nguyen Hoang Anh, Pham Huu Kien, Toshiaki Iitaka and Nguyen Van Hong

Topology of SiO x units and glassy network of magnesium silicate glass at different pressures are investigated by molecular dynamics simulation to clarify its microstructure under compression. Results show that SiO x -topology and glassy network structure are significantly dependent on pressure. At ambient pressure, the –Si–O– glassy network in Mg 2 SiO 4 glass is split into subnets/clusters. Under compression, the small subnets tend to merge each other forming larger ones. The decrease of Si–O–Si bond angle under compression that accompanies a formation of edge- and face-sharing bonds between SiO x units results in the first peak splitting of Si–Si PRDF at high pressure. In particular, the investigation also reveals a tight correlation between PRDFs (Si–Si, Mg–Mg, Si–Mg, O–O) and BADs (Si–O–Si, Mg–O–Mg, Mg–O–Si, O–T–O (T = Si, Mg)), respectively. The spatial distribution of corner-, edge- and face-sharin...

Modelling and Simulation in Materials Science and Engineering

Denuded zones in zirconium pressure vessels: oxygen’s role examined via multi-scale diffusion model

Manura Liyanage, Ronald Miller and R K N D Rajapakse

Zirconium alloys are extensively used as cladding material in nuclear reactors. They are vulnerable to hydrogen degradation under the harsh service conditions of the reactors. Optical micrographs taken in some pressure tubes shows the presence of hydride denuded zones closer to the surface, where the hydrides formed in this region are smaller in size compared to the bulk. We investigated the effect of oxygen on diffusivity of hydrogen in α Zr, to check the hypothesis that oxygen slows the diffusion of hydrogen and thereby encourages the occurrence of hydride denuded zones. We used a multi-scale model to simulate H diffusion in Zr with different O concentrations to identify the effect that O has on H diffusivity. From the study we found that oxygen indeed decreases the diffusivity of hydrogen in α Zr for moderate oxygen concentrations. We investigated the diffusion processes of individual H atoms, which showed that the reduction in diffusivity is caused by a decrease in the hoppi...

Modelling and Simulation in Materials Science and Engineering

July 08 2020

Coherent Multispin Exchange Coupling in a Quantum-Dot Spin Chain

Haifeng Qiao, Yadav P. Kandel, Kuangyin Deng, Saeed Fallahi, Geoffrey C. Gardner, Michael J. Manfra, Edwin Barnes, and John M. Nichol

A new method for controlling interactions among multiple electron spins allows for efficient information transfer between distant qubits, opening the door to many scalable quantum computing applications.

Physical Review X

Stochastic and Quantum Thermodynamics of Driven RLC Networks

Nahuel Freitas, Jean-Charles Delvenne, and Massimiliano Esposito

A theory for describing heat flow in simple electronic circuits reveals limits of traditional analysis techniques, paving the way for design improvements in the design of thermal machines with electronic circuits.

Physical Review X

Robust Dynamic Hamiltonian Engineering of Many-Body Spin Systems

Joonhee Choi, Hengyun Zhou, Helena S. Knowles, Renate Landig, Soonwon Choi, and Mikhail D. Lukin

A new framework for engineering quantum many-body systems uses pulsed periodic driving to tailor the system’s Hamiltonian, setting the stage for improved quantum applications such as information processing, metrology, and simulation.

Physical Review X

Quantum Metrology with Strongly Interacting Spin Systems

Hengyun Zhou, Joonhee Choi, Soonwon Choi, Renate Landig, Alexander M. Douglas, Junichi Isoya, Fedor Jelezko, Shinobu Onoda, Hitoshi Sumiya, Paola Cappellaro, Helena S. Knowles, Hongkun Park, and Mikhail D. Lukin

A new approach to quantum sensing uses a tailored control pulse sequence to overcome sensor-sensor interactions that have plagued previous designs, setting the stage for nanoscale sensing with newfound sensitivity.

Physical Review X

Fragile Phases as Affine Monoids: Classification and Material Examples

Zhi-Da Song, Luis Elcoro, Yuan-Feng Xu, Nicolas Regnault, and B. Andrei Bernevig

A complete classification of a subset of so-called “fragile” topological states offers predictions for hundreds of realistic materials in which these exotic and little-understood states may appear.

Physical Review X

Algorithmic Complexity of Multiplex Networks

Andrea Santoro and Vincenzo Nicosia

A new measure of complexity of multilayer networks shows that these systems can encode an optimal amount of additional information compared to their single-layer counterparts and provides a powerful tool for their analysis.

Physical Review X

Spectral Evidence of Squeezing of a Weakly Damped Driven Nanomechanical Mode

J. S. Huber, G. Rastelli, M. J. Seitner, J. Kölbl, W. Belzig, M. I. Dykman, and E. M. Weig

A new technique for detecting “squeezed” fluctuations does so in a single measurement, as opposed to tracking phase fluctuations over time, setting the stage for improved high-resolution sensing.

Physical Review X

Fast Navigation in a Large Hilbert Space Using Quantum Optimal Control

Arthur Larrouy, Sabrina Patsch, Rémi Richaud, Jean-Michel Raimond, Michel Brune, Christiane P. Koch, and Sébastien Gleyzes

By carefully shaping radio frequency pulses, experiments show how to quickly and efficiently prepare a single atom in one of several desired states, a key ability for a variety of quantum technologies.

Physical Review X

Distribution of Topological Types in Grain-Growth Microstructures

Emanuel A. Lazar, Jeremy K. Mason, Robert D. MacPherson, and David J. Srolovitz

An open question in studying normal grain growth concerns the asymptotic state to which microstructures converge. In particular, the distribution of grain topologies is unknown. We introduce a thermodynamiclike theory to explain these distributions in two- and three-dimensional systems. In particula...

Physical Review Letters

Colossal Pressure-Induced Softening in Scandium Fluoride

Zhongsheng Wei, Lei Tan, Guanqun Cai, Anthony E. Phillips, Ivan da Silva, Mark G. Kibble, and Martin T. Dove

The counterintuitive phenomenon of pressure-induced softening in materials is likely to be caused by the same dynamical behavior that produces negative thermal expansion. Through a combination of molecular dynamics simulation on an idealized model and neutron diffraction at variable temperature and ...

Physical Review Letters

Separating Hydrocarbon Mixtures by Driving the Components in Opposite Directions: High Degree of Separation Factor and Energy Efficiency

Shubhadeep Nag, G. Ananthakrishna, Prabal K. Maiti, and Subramanian Yashonath

A radically different approach for separation of molecular mixtures is proposed. A judicious combination of levitation effect observed in zeolites with a counter intuitive Landauer blow torch effect provides driving forces for the two components of the mixture to move in opposite directions. Using n...

Physical Review Letters

Two-Scale Scenario of Rigidity Percolation of Sticky Particles

Yuchuan Wang, Sheng Fang, Ning Xu, and Youjin Deng

In the presence of attraction, the jamming transition of packings of frictionless particles corresponds to the rigidity percolation. When the range of attraction is long, the distribution of the size of rigid clusters, $P(s)$, is continuous and shows a power-law decay. For systems with short-range a...

Physical Review Letters

St. Petersburg Paradox and Failure Probability

Jake Fontana and Peter Palffy-Muhoray

Stretching fibers until they fail reveals a correspondence between material strength and a 300-year-old math puzzle involving coin flips.

Physical Review Letters

From first- to second-order phase transitions in hybrid improper ferroelectrics through entropy stabilization

Fernando Pomiro, Chris Ablitt, Nicholas C. Bristowe, Arash A. Mostofi, Choongjae Won, Sang-Wook Cheong, and Mark S. Senn

Hybrid improper ferroelectrics (HIFs) have been studied intensively over the past few years to gain an understanding of their temperature-induced phase transitions and ferroelectric switching pathways. Here we report a switching from a first- to a second-order phase transition pathway for HIFs ${\ma...

Physical Review B Structure, Structural phase transitions, Mechanical properties, Defects

Temperature and pressure manipulation of magnetic ordering and phonon dynamics with phase transition in multiferroic ${\mathrm{GdFeO}}_{3}$: Evidence from Raman scattering

Yan Ye (叶艳), Anyang Cui (崔安阳), Mengyun Bian (卞梦云), Kai Jiang (姜凯), Liangqing Zhu (朱亮清), Jinzhong Zhang (张金中), Liyan Shang (商丽燕), Yawei Li (李亚巍), Zhigao Hu (胡志高), and Junhao Chu (褚君浩)

We systematically investigate the detailed dynamics of the phonon and local structure of rare-earth orthoferrites ${\mathrm{GdFeO}}_{3}$ single crystal with temperature and pressure induced structural/magnetic phase transition by Raman spectroscopy. Phonon evolution related to the motion of octahedr...

Physical Review B Structure, Structural phase transitions, Mechanical properties, Defects

Recovery of a high-pressure phase formed under laser-driven compression

M. G. Gorman, D. McGonegle, S. J. Tracy, S. M. Clarke, C. A. Bolme, A. E. Gleason, S. J. Ali, S. Hok, C. W. Greeff, P. G. Heighway, K. Hulpach, B. Glam, E. Galtier, H. J. Lee, J. S. Wark, J. H. Eggert, J. K. Wicks, and R. F. Smith

The recovery of metastable structures formed at high pressure has been a long-standing goal in the field of condensed matter physics. While laser-driven compression has been used as a method to generate novel structures at high pressure, to date no high-pressure phases have been quenched to ambient ...

Physical Review B Structure, Structural phase transitions, Mechanical properties, Defects

Origin of mean-field behavior in an elastic Ising model

Layne B. Frechette, Christoph Dellago, and Phillip L. Geissler

Simple elastic models of spin-crossover compounds are known empirically to exhibit classical critical behavior. We demonstrate how the long-range interactions responsible for this behavior arise naturally upon integrating out mechanical fluctuations of such a model. A mean-field theory applied to th...

Physical Review B Structure, Structural phase transitions, Mechanical properties, Defects

Experimental validation of the theoretical prediction for the optical $S$ matrix

A. M. Martínez-Argüello, V. Domínguez-Rocha, R. A. Méndez-Sánchez, and M. Martínez-Mares

Scattering of waves is present in many areas of physics. Within all these areas, in a great number of systems, the scattering can be separated in an averaged response that crosses rapidly the scattering region and a fluctuating delayed response. This fact is the basis of the optical model; the avera...

Physical Review B Structure, Structural phase transitions, Mechanical properties, Defects

Blocking of the martensitic transition at the nanoscale in a ${\mathrm{Ti}}_{2}\mathrm{NiCu}$ wedge

Petr Lega, Alexey Kartsev, Ilya Nedospasov, Shuhui Lv, Xiaoling Lv, Natalia Tabachkova, Artemy Irzhak, Andrey Orlov, and Victor Koledov

Shape memory effect associated with martensitic transformations is a rapidly developing field in nanotechnologies, where industrial use of systems established on that effect provide greater flexibility on the nanodevice fabrications of various kinds. And therefore it addresses questions to the phase...

Physical Review B Structure, Structural phase transitions, Mechanical properties, Defects

Structure of amorphous ${\mathrm{Cu}}_{2}{\mathrm{GeTe}}_{3}$ and the implications for its phase-change properties

Jens R. Stellhorn, Benedict Paulus, Shinya Hosokawa, Wolf-Christian Pilgrim, Nathalie Boudet, Nils Blanc, Hiroyuki Ikemoto, Shinji Kohara, and Yuji Sutou

The structure of amorphous ${\mathrm{Cu}}_{2}{\mathrm{GeTe}}_{3}$ is investigated by a combination of anomalous x-ray scattering and extended x-ray absorption fine-structure experiments. The experimental data are analyzed with reverse Monte Carlo modeling, and they are interpreted in terms of short-...

Physical Review B Structure, Structural phase transitions, Mechanical properties, Defects

$\mathcal{PT}$-symmetric chiral metamaterials: Asymmetric effects and $\mathcal{PT}$-phase control

Ioannis Katsantonis, Sotiris Droulias, Costas M. Soukoulis, Eleftherios N. Economou, and Maria Kafesaki

We investigate the influence of chirality on the $\mathcal{PT}$-symmetric and $\mathcal{PT}$-broken phase of $\mathcal{PT}$-symmetric chiral systems. Starting from the point that transverse magnetic (TM) and transverse electric (TE) waves have different exceptional points, we show that with circular...

Physical Review B Structure, Structural phase transitions, Mechanical properties, Defects

Chaotic dynamics in shear-band-mediated plasticity of metallic glasses

Baoan Sun, Liping Yu, Gang Wang, Xing Tong, Chuan Geng, Jingtao Wang, Jingli Ren, and Weihua Wang

The chaotic dynamics describes how a small change of initial conditions can result in a large difference in a deterministic nonlinear system, i.e., the “butterfly effect.” Through a combination of experimental and theoretical analysis, here we showed unambiguously that the deformation of metallic gl...

Physical Review B Structure, Structural phase transitions, Mechanical properties, Defects

Data-driven exploration and continuum modeling of dislocation networks

Markus Sudmanns, Jakob Bach, Daniel Weygand and Katrin Schulz

The microstructural origin of strain hardening during plastic deformation in stage II deformation of face-centered cubic (fcc) metals can be attributed to the increase in dislocation density resulting in a formation of dislocation networks. Although this is a well known relation, the complexity of dislocation multiplication processes and details about the formation of dislocation networks have recently been revealed by discrete dislocation dynamics (DDD) simulations. It has been observed that dislocations, after being generated by multiplication mechanisms, show a limited expansion within their slip plane before they get trapped in the network by dislocation reactions. This mechanism involves multiple slip systems and results in a heterogeneous dislocation network, which is not reflected in most dislocation-based continuum models. We approach the continuum modeling of dislocation networks by using data science methods to provide a link between discrete dislocations and the conti...

Modelling and Simulation in Materials Science and Engineering

Prediction of pore evolution during selected laser melting solidification by a finite element-phase field model

Yilin Liu, Gang Wang and Dechang Zeng

Porosity control in parts built by additive manufacturing is still a great challenge. In this work, we developed a finite element-phase field model to simulate pore evolution during selected laser melting solidification, and focused on the effects of energy density on the porosity. The model reproduced the solidification phenomena observed experimentally and revealed the quantitative relation between porosity and energy density. It was found that the critical energy density of Ti-6Al-4V alloy for full densification is 45 J mm −3 to 75 J mm −3 , which is in good accord with the experimental results.

Modelling and Simulation in Materials Science and Engineering

Sparse thermal data for cellular automata modeling of grain structure in additive manufacturing

Matthew Rolchigo, Benjamin Stump, James Belak and Alex Plotkowski

Grain growth in the wake of the melt pool formed during alloy-based additive manufacturing (AM) is complex and multifaceted, depending on parameters governing heat transport, fluid flow, and solidification itself. Cellular automata (CA) models have proven effective in providing computationally efficient and physically sound predictions of grain structure for several AM problems, but their efficiency is tied to the performance of heat transport models. CA models use only a small portion of the problem’s temperature data (near the moving melt pool boundary), and much of the CA calculations do not affect the final result due to re-melting of material. Coupling of and communication between heat transport and solidification models, and eliminating operations irrelevant towards final grain structure prediction, will be necessary for using these methods for efficient simulation of large parts. We introduce a procedure of decoupling the CA from temperature field simulation, using files ...

Modelling and Simulation in Materials Science and Engineering

Sensitivity analysis of a phase field model for static recrystallization of deformed microstructures

Susan P Gentry and Katsuyo Thornton

Static recrystallization is a process whereby dislocation-free grains are nucleated in a deformed microstructure and then newly recrystallized grains grow and consume the previously existing grains. This paper describes a phase field model for static recrystallization, along with details of the implementation and simulation results. Recrystallized grains are seeded utilizing a probability-based method, including a hold time to allow the order parameters to adjust to seeded grains. The nominal simulation time is corrected to account for the nuclei hold and for the time required for a nucleus to grow from its critical size to the seeded size. Microstructural evolution was simulated for two- and three-dimensional systems and the fraction recrystallized was quantified via Avrami kinetics. The resulting Avrami time exponents were in agreement with the expected values for site-saturated nucleation. The variability in the Avrami parameters was quantified by simulating the recrystalliza...

Modelling and Simulation in Materials Science and Engineering

June 15 2020

Comment on “Equilibration Time Scales of Physically Relevant Observables”

Robin Heveling, Lars Knipschild, and Jochen Gemmer

Putting a generally valid upper bound on equilibration times of physically relevant observables is a much pursued endeavor. Recently, such a bound has been suggested by Garcia-Pintos et al. While the mathematical correctness of the bound as such is undisputed, its concrete calculation requires the k...

Physical Review X

Quantum Erasure Using Entangled Surface Acoustic Phonons

A. Bienfait, Y. P. Zhong, H.-S. Chang, M.-H. Chou, C. R. Conner, É. Dumur, J. Grebel, G. A. Peairs, R. G. Povey, K. J. Satzinger, and A. N. Cleland

A new experiment implements a quantum eraser using phonons rather than light, erasing information about which path a phonon travels in an interferometer to recover the interference pattern.

Physical Review X

Isotropic Chiral Acoustic Phonons in 3D Quasicrystalline Metamaterials

Yi Chen, Muamer Kadic, Sébastien Guenneau, and Martin Wegener

The elastic properties of three-dimensional (3D) crystalline mechanical metamaterials, unlike those of amorphous structures, are generally strongly anisotropic—even in the long-wavelength limit and for highly symmetric crystals. Aiming at isotropic linear elastic wave propagation, we therefore study...

Physical Review Letters

What Determines the fcc-bcc Structural Transformation in Shock Compressed Noble Metals?

Surinder M. Sharma, Stefan J. Turneaure, J. M. Winey, and Y. M. Gupta

High pressure structural transformations are typically characterized by the thermodynamic state (pressure-volume-temperature) of the material. We present in situ x-ray diffraction measurements on laser-shock compressed silver and platinum to determine the role of deformation-induced lattice defects ...

Physical Review Letters

Phase diagram of ferroelectrics with tricritical and Lifshitz points at coupling between polar and antipolar fluctuations

V. Liubachko, A. Oleaga, A. Salazar, R. Yevych, A. Kohutych, and Yu. Vysochanskii

Available experimental data about static and dynamic critical behaviors of ${\text{Sn}}_{2}{\text{P}}_{2}{\text{S}}_{6}$-type ferroelectrics and $({\mathrm{Pb}}_{y}{\mathrm{Sn}}_{1−y}{)}_{2}{\mathrm{P}}_{2}{({\mathrm{Se}}_{x}{\mathrm{S}}_{1−x})}_{6}$ mixed crystals with a line of tricritical points ...

Physical Review B Structure, Structural phase transitions, Mechanical properties, Defects

Distinct intermediate states in the isostructural $R\text{−}3m$ phase of the topological insulator $\mathrm{B}{\mathrm{i}}_{2}\mathrm{S}{\mathrm{e}}_{3}$ at high pressure

Xinguo Hong, Matt Newville, Yang Ding, Tetsuo Irifune, Genda Gu, and Ho-Kwang Mao

The electronic state of layered three-dimensional topological insulators at high pressure is a compelling but a puzzling hot topic. The open question is the structural origins for the pressure-induced novel physics of electronic topological transition (ETT), topological superconductivity, and Majora...

Physical Review B Structure, Structural phase transitions, Mechanical properties, Defects

Phonon thermodynamics and elastic behavior of GaAs at high temperatures and pressures

Jane E. Herriman and Brent Fultz

The phonons of wurtzite and zinc blende GaAs were calculated at simultaneously elevated temperature and pressure, and elastic constants were calculated as functions of pressure. Pressure caused instabilities of shorter-wavelength transverse acoustic modes in both wurtzite and zinc blende GaAs, causi...

Physical Review B Structure, Structural phase transitions, Mechanical properties, Defects

Fermi surface studies of the low-temperature structure of sodium

S. F. Elatresh, Mohammad Tomal Hossain, Tushar Bhowmick, A. D. Grockowiak, Weizhao Cai, W. A. Coniglio, Stanley W. Tozer, N. W. Ashcroft, S. A. Bonev, Shanti Deemyad, and Roald Hoffmann

Sodium is the most abundant alkali-metal element and has one of the simplest electronic structures of any metal. At ambient conditions, sodium forms a body-centered-cubic lattice. However, during cooling, it undergoes a partial martensitic phase transition to a complex mixture of rhombohedral polyty...

Physical Review B Structure, Structural phase transitions, Mechanical properties, Defects

Sodium-potassium system at high pressure

Mungo Frost, Emma E. McBride, Maximilian Schörner, Ronald Redmer, and Siegfried H. Glenzer

Mixtures of sodium and potassium differ substantially from the pure elements, while retaining the high compressibility, which is important to the complex behavior of dense alkali metals. We present powder x-ray diffraction of mixtures of Na and K compressed in diamond anvil cells to 48 GPa at 295 K....

Physical Review B Structure, Structural phase transitions, Mechanical properties, Defects

Role of graphite crystal structure on the shock-induced formation of cubic and hexagonal diamond

Travis J. Volz, Stefan J. Turneaure, Surinder M. Sharma, and Y. M. Gupta

During shock wave compression at about 500,000 atm of pressure and of about 100 nanoseconds duration, graphite is transformed into either hexagonal diamond or cubic diamond, depending on the crystal structure of the graphite crystallites that make up the sample. The figure shows x-ray diffraction data for two types of graphite: (a) and (b) show data for graphite crystallites having hexagonal structure, while (c) and (d) show data for graphite crystallites having turbostratic structure.

Physical Review B Structure, Structural phase transitions, Mechanical properties, Defects

Evolutionary construction of a formation-energy convex hull: Practical scheme and application to a carbon-hydrogen binary system

Takahiro Ishikawa and Takashi Miyake

We present an evolutionary construction technique of formation-energy convex hull to search for thermodynamically stable compounds. In this technique, candidates with a wide variety of chemical compositions and crystal structures are created by systematically applying evolutionary operators, “mating...

Physical Review B Structure, Structural phase transitions, Mechanical properties, Defects

Modeling mechanical relaxation in incommensurate trilayer van der Waals heterostructures

Ziyan Zhu, Paul Cazeaux, Mitchell Luskin, and Efthimios Kaxiras

The incommensurate stacking of multilayered two-dimensional materials is a challenging problem from a theoretical perspective and an intriguing avenue for manipulating their physical properties. Here we present a multiscale model to obtain the mechanical relaxation pattern of twisted trilayer van de...

Physical Review B Structure, Structural phase transitions, Mechanical properties, Defects

June 08 2020

Reflection Matrix Approach for Quantitative Imaging of Scattering Media

William Lambert, Laura A. Cobus, Mathieu Couade, Mathias Fink, and Alexandre Aubry

A new way of focusing waves creates a variety of new types of images that will be decisive for biomedical diagnosis in ultrasound imaging and optical microscopy, nondestructive evaluation in industry, and monitoring in geophysics.

Physical Review X

Revealing Dynamics, Communities, and Criticality from Data

Deniz Eroglu, Matteo Tanzi, Sebastian van Strien, and Tiago Pereira

A technique for analyzing complex networks can predict, with limited time-series data, critical transitions before they occur. Such insight could help model and predict changes in a neuronal network.

Physical Review X

Prethermalization without Temperature

David J. Luitz, Roderich Moessner, S. L. Sondhi, and Vedika Khemani

Optimal application of a magnetic field can increase the lifetime of transient time crystals by orders of magnitude, and autocorrelation functions can distinguish transient time crystals from infinitely long-lived ones.

Physical Review X

Floquet Prethermalization in a Bose-Hubbard System

Antonio Rubio-Abadal, Matteo Ippoliti, Simon Hollerith, David Wei, Jun Rui, S. L. Sondhi, Vedika Khemani, Christian Gross, and Immanuel Bloch

An exponential suppression of heating has been observed in a periodically driven optical lattice, opening up an opportunity to engineer new states of matter.

Physical Review X

Anomalous Correlators in Nonlinear Dispersive Wave Systems

Joseph Zaleski, Miguel Onorato, and Yuri V. Lvov

An extension to wave turbulence theory shows that in a system of nonlinear waves, correlations among the waves arise, causing “ghost” excitations that lead to coherent structures in physical space.

Physical Review X

Lattice Gauge Theories and String Dynamics in Rydberg Atom Quantum Simulators

Federica M. Surace, Paolo P. Mazza, Giuliano Giudici, Alessio Lerose, Andrea Gambassi, and Marcello Dalmonte

Recent experiments with excited cold-atom gases emulate a gauge theory that describes 1D quantum electrodynamics, insight that could help with the development of tabletop experiments for probing extreme states of matter.

Physical Review X

Exact Generalized Kohn-Sham Theory for Hybrid Functionals

Rachel Garrick, Amir Natan, Tim Gould, and Leeor Kronik

A rigorous analysis of one of the mathematical workhorses used in density-functional-theory calculations provides exact definitions and relations that could help improve predictions of material and molecular properties.

Physical Review X

Tricritical Physics in Two-Dimensional $p$-Wave Superfluids

Fan Yang, Shao-Jian Jiang, and Fei Zhou

We study effects of quantum fluctuations on two-dimensional $p+ip$ superfluids near resonance. In the standard paradigm, phase transitions between superfluids and zero density vacuum are continuous. When strong quantum fluctuations near resonance are present, the line of continuous phase transitions...

Physical Review Letters

Observation of High-Frequency Transverse Phonons in Metallic Glasses

X. Y. Li, H. P. Zhang, S. Lan, D. L. Abernathy, T. Otomo, F. W. Wang, Y. Ren, M. Z. Li, and X.-L. Wang

Using inelastic neutron scattering and molecular dynamics simulations on a model Zr-Cu-Al metallic glass, we show that transverse phonons persist well into the high-frequency regime, and can be detected at large momentum transfer. Furthermore, the apparent peak width of the transverse phonons was fo...

Physical Review Letters

Glass Stability Changes the Nature of Yielding under Oscillatory Shear

Wei-Ting Yeh, Misaki Ozawa, Kunimasa Miyazaki, Takeshi Kawasaki, and Ludovic Berthier

We perform molecular dynamics simulations to investigate the effect of a glass preparation on its yielding transition under oscillatory shear. We use swap Monte Carlo to investigate a broad range of glass stabilities from poorly annealed to highly stable systems. We observe a qualitative change in t...

Physical Review Letters

Atomic Diffusion in $α$-iron across the Curie Point: An Efficient and Transferable Ab Initio –Based Modeling Approach

Anton Schneider, Chu-Chun Fu, Frédéric Soisson, and Cyrille Barreteau

An accurate prediction of atomic diffusion in Fe alloys is challenging due to thermal magnetic excitations and magnetic transitions. We propose an efficient approach to address these properties via a Monte Carlo simulation, using ab initio–based effective interaction models. The temperature evolutio...

Physical Review Letters

High-Pressure Polymeric Nitrogen Allotrope with the Black Phosphorus Structure

Dominique Laniel, Bjoern Winkler, Timofey Fedotenko, Anna Pakhomova, Stella Chariton, Victor Milman, Vitali Prakapenka, Leonid Dubrovinsky, and Natalia Dubrovinskaia

Studies of polynitrogen phases are of great interest for fundamental science and for the design of novel high energy density materials. Laser heating of pure nitrogen at 140 GPa in a diamond anvil cell led to the synthesis of a polymeric nitrogen allotrope with the black phosphorus structure, bp-N. ...

Physical Review Letters

Calculation of Mode Grüneisen Parameters Made Simple

David Cuffari and Angelo Bongiorno

A novel method to calculate mode Grüneisen parameters of a material from first principles is presented. This method overcomes the difficulties and limitations of existing approaches, based on the calculation of either third-order force constants or phonon frequencies at different volumes. Our method...

Physical Review Letters

Angular Momentum in Rotating Superfluid Droplets

Sean M. O. O’Connell, Rico Mayro P. Tanyag, Deepak Verma, Charles Bernando, Weiwu Pang, Camila Bacellar, Catherine A. Saladrigas, Johannes Mahl, Benjamin W. Toulson, Yoshiaki Kumagai, Peter Walter, Francesco Ancilotto, Manuel Barranco, Marti Pi, Christoph Bostedt, Oliver Gessner, and Andrey F. Vilesov

The angular momentum of rotating superfluid droplets originates from quantized vortices and capillary waves, the interplay between which remains to be uncovered. Here, the rotation of isolated submicrometer superfluid $^{4}\mathrm{He}$ droplets is studied by ultrafast x-ray diffraction using a free ...

Physical Review Letters

Superfluid and Supersolid Phases of $^{4}\mathrm{He}$ on the Second Layer of Graphite

M. C. Gordillo and J. Boronat

We revisited the phase diagram of the second layer of $^{4}\mathrm{He}$ on top of graphite using quantum Monte Carlo methods. Our aim was to explore the existence of the novel phases suggested recently in experimental works, and determine their properties and stability limits. We found evidence of a...

Physical Review Letters

Field-Dependent Ionic Conductivities from Generalized Fluctuation-Dissipation Relations

Dominika Lesnicki, Chloe Y. Gao, Benjamin Rotenberg, and David T. Limmer

We derive a relationship for the electric field dependent ionic conductivity in terms of fluctuations of time integrated microscopic variables. We demonstrate this formalism with molecular dynamics simulations of solutions of differing ionic strength with implicit solvent conditions and molten salts...

Physical Review Letters

High Explosive Ignition through Chemically Activated Nanoscale Shear Bands

Matthew P. Kroonblawd and Laurence E. Fried

Shock initiation and detonation of high explosives is considered to be controlled through hot spots, which are local regions of elevated temperature that accelerate chemical reactions. Using classical molecular dynamics, we predict the formation of nanoscale shear bands through plastic failure in sh...

Physical Review Letters

Origin of the Bauschinger Effect in Amorphous Solids

Sylvain Patinet, Armand Barbot, Matthias Lerbinger, Damien Vandembroucq, and Anaël Lemaître

We study the structural origin of the Bauschinger effect by accessing numerically the local plastic thresholds in the steady state flow of a two-dimensional model glass under athermal quasistatic deformation. More specifically, we compute the local residual strength, $\mathrm{Δ}{τ}^{c}$, for arbitra...

Physical Review Letters

Stacking Domains and Dislocation Networks in Marginally Twisted Bilayers of Transition Metal Dichalcogenides

V. V. Enaldiev, V. Zólyomi, C. Yelgel, S. J. Magorrian, and V. I. Fal’ko

We apply a multiscale modeling approach to study lattice reconstruction in marginally twisted bilayers of transition metal dichalcogenides (TMD). For this, we develop density functional theory parametrized interpolation formulae for interlayer adhesion energies of ${\mathrm{MoSe}}_{2}$, ${\mathrm{WS...

Physical Review Letters

Controlling the electrical and magnetic ground states by doping in the complete phase diagram of titanate ${\mathrm{Eu}}_{1−x}{\mathrm{La}}_{x}{\mathrm{TiO}}_{3}$ thin films

Hyungki Shin, Chong Liu, Fengmiao Li, Ronny Sutarto, Bruce A. Davidson, and Ke Zou

${\mathrm{EuTiO}}_{3}$, a band insulator, and ${\mathrm{LaTiO}}_{3}$, a Mott insulator, are both antiferromagnetic with transition temperatures ∼5.5 and ∼160 K, respectively. Here, we report the synthesis of ${\mathrm{Eu}}_{1−x}{\mathrm{La}}_{x}{\mathrm{TiO}}_{3}$ thin films with $x=0$ to 1 by oxide...

Physical Review B Structure, Structural phase transitions, Mechanical properties, Defects

Tight-binding modeling of interstitial ordering processes in metals: Application to zirconium hydrides

Paul Eyméoud, Fabienne Ribeiro, Azzam Charaf-Eddin, Rémy Besson, and Guy Tréglia

We present here a theoretical study of ordering processes in metal-hydrogen compounds based on a generalized perturbation method and on tight-binding coherent potential approximation. This approach is illustrated for zirconium hydrides, in which case we demonstrate that a cluster expansion of the or...

Physical Review B Structure, Structural phase transitions, Mechanical properties, Defects

Ge coordination in $\mathrm{NaAlG}{\mathrm{e}}_{3}{\mathrm{O}}_{8}$ glass upon compression to 131 GPa

Marija Krstulović, Angelika D. Rosa, Nicole Biedermann, Georg Spiekermann, Tetsuo Irifune, Manuel Muñoz, and Max Wilke

Structural transformations at high pressure in $\mathrm{NaAlG}{\mathrm{e}}_{3}{\mathrm{O}}_{8}$ glass were investigated by means of x-ray absorption spectroscopy at the Ge $K$ edge in combination with a diamond anvil cell. The obtained results provide a detailed picture of the local structural behav...

Physical Review B Structure, Structural phase transitions, Mechanical properties, Defects

Unveiling the medium-range order in glass models and its role in glass formation

Xinyu Fan, Yang Sun, Cai-Zhuang Wang, Kai-Ming Ho, M. S. Altman, and Li Huang

The correlation between structure and glass formability in glassy systems is a long-standing puzzle. To solve this puzzle, many descriptors based on the short-range order (SRO) have been proposed. Here we show that the SRO, however, offers little help in explaining the glass formability and stabilit...

Physical Review B Structure, Structural phase transitions, Mechanical properties, Defects

Structural distortions in rare-earth transition-metal oxide perovskites under high pressure

J.-S. Zhou

Owing to their structural complexity and wide range of possible chemical combinations, perovskite oxides exhibit many technically important physical properties. Pressure is a thermodynamic parameter which is useful for tuning physical properties; however, the response of the complex crystal structur...

Physical Review B Structure, Structural phase transitions, Mechanical properties, Defects

${\mathrm{BaZrO}}_{3}$ stability under pressure: The role of nonlocal exchange and correlation

Erik Jedvik Granhed, Göran Wahnström, and Per Hyldgaard

The ground-state structure of ${\mathrm{BaZrO}}_{3}$ is experimentally known to be cubic down to absolute zero. However, there exist several measured properties and experimental characterizations that earlier computational works have failed to accurately describe and explain within this cubic symmet...

Physical Review B Structure, Structural phase transitions, Mechanical properties, Defects

Antichiral one-way edge states in a gyromagnetic photonic crystal

Jianfeng Chen, Wenyao Liang, and Zhi-Yuan Li

We propose and show that antichiral edge states can be realized in a gyromagnetic photonic crystal (GPC) with a honeycomb lattice consisting of two interpenetrating triangular sublattices $A$ and $B$. When sublattices $A$ and $B$ are immersed in opposite external magnetic fields respectively, the ba...

Physical Review B Structure, Structural phase transitions, Mechanical properties, Defects

Room-temperature polar metal stabilized under high pressure

J.-J. Gao, S.-Y. Fu, K. Yamaura, J. F. Lin, and J.-S. Zhou

$\mathrm{LiOs}{\mathrm{O}}_{3}$ synthesized under high pressure in recent years is a rare metal since it undergoes a nonpolar to polar phase transition at ${T}_{s}=140\phantom{\rule{0.16em}{0ex}}\mathrm{K}$. Forming a polar axis through a phase transition in a metal seems against common sense. It is...

Physical Review B Structure, Structural phase transitions, Mechanical properties, Defects

Pseudospin induced topological corner state at intersecting sonic lattices

Zhiwang Zhang, Bolun Hu, Feng Liu, Ying Cheng, Xiaojun Liu, and Johan Christensen

Inspired by the discoveries of electronic topological phases and topological insulators, topologically protected boundary states in classical wave-based systems have attracted considerable interest in the last decade. Most recently, acoustic higher-order topological insulators and Kekulé-distorted s...

Physical Review B Structure, Structural phase transitions, Mechanical properties, Defects

Ferrotoroidic polarons in antiferrodistortive $\mathrm{SrTi}{\mathrm{O}}_{3}$

Takahiro Shimada, Yuuki Ichiki, Gen Fujimoto, Le Van Lich, Tao Xu, Jie Wang, and Hiroyuki Hirakata

Discovery of new quasiparticles with nontrivial topological field textures, such as polar vortices, skyrmions, and merons, holds promise in technological paradigms. Here, the authors demonstrate a ferroelectric quasiparticle with topological polarization vortices by engineering excess electron polarons. They further show that the electron polaron carries a magnetic moment coupled with ferrotoroidicity, i.e., the magnetoelectric effect. This result provides insight into the ultimate miniaturization of ferrotoroic materials and a new class of functional polaron families.

Physical Review B Structure, Structural phase transitions, Mechanical properties, Defects

Experimental evidence for the elastic long-range character of the spin crossover transition in cooperative single crystals

Houcem Fourati and Kamel Boukheddaden

We evidenced by means of optical microscopy the long-range character of the interactions acting in spin crossover (SCO) single crystals through a study of the optical density (OD) variation during the spin transition between high-spin (HS) and low-spin (LS) states. The time evolution of the local OD...

Physical Review B Structure, Structural phase transitions, Mechanical properties, Defects

Simulating a quantum commensurate-incommensurate phase transition using two Raman-coupled one-dimensional condensates

V. Kasper, J. Marino, S. Ji, V. Gritsev, J. Schmiedmayer, and E. Demler

We study a transition between a homogeneous and an inhomogeneous phase in a system of one-dimensional, Raman tunnel-coupled Bose gases. The homogeneous phase shows a flat density and phase profile, whereas the inhomogeneous ground state is characterized by periodic density ripples and a soliton stai...

Physical Review B Structure, Structural phase transitions, Mechanical properties, Defects

Compression behavior of dense ${\mathrm{H}}_{2}\text{−}\mathrm{He}$ mixtures up to 160 GPa

Jinhyuk Lim, Minseob Kim, Sakun Duwal, Saori Kawaguchi, Yasuo Ohishi, Hanns-Peter Liermann, Rostislav Hrubiak, John S. Tse, and Choong-Shik Yoo

We have studied the compression behavior of ${\mathrm{H}}_{2}\text{−}\mathrm{He}$ mixtures in comparison with pure ${\mathrm{H}}_{2}$ and He using powder synchrotron x-ray diffraction, and we present the pressure-volume (PV) compression data of ${\mathrm{H}}_{2}\text{−}\mathrm{He}$ mixtures to 160 G...

Physical Review B Structure, Structural phase transitions, Mechanical properties, Defects

First-principles study of two-dimensional electron and hole gases at the head-to-head and tail-to-tail ${180}^{∘}$ domain walls in ${\mathrm{PbTiO}}_{3}$ ferroelectric thin films

James Sifuna, Pablo García-Fernández, George S. Manyali, George Amolo, and Javier Junquera

We study from first principles the structural and electronic properties of head-to-head (HH) and tail-to-tail (TT) ${180}^{∘}$ domain walls in isolated free-standing ${\mathrm{PbTiO}}_{3}$ slabs. For sufficiently thick domains $(n=16$ unit cells of ${\mathrm{PbTiO}}_{3})$, a transfer of charge from ...

Physical Review B Structure, Structural phase transitions, Mechanical properties, Defects

Sampling strategy in efficient potential energy surface mapping for predicting atomic diffusivity in crystals by machine learning

Kazuaki Toyoura, Takeo Fujii, Kenta Kanamori, and Ichiro Takeuchi

We propose a machine-learning-based method for efficiently predicting atomic diffusivity in crystals, in which the potential energy surface (PES) of a diffusion carrier is partially evaluated by first-principles calculations. To preferentially evaluate the region of interest governing the atomic dif...

Physical Review B Structure, Structural phase transitions, Mechanical properties, Defects

Theoretical investigations on the pressure effects in spin-crossover materials: Reentrant phase transitions and other behavior

Killian Babilotte and Kamel Boukheddaden

Pressure effects have been widely studied in spin-crossover (SCO) solids due to their immediate influence on the thermal dependence of the high-spin (HS) fraction. In most of the cooperative SCO materials, the applied pressure shifts the transition temperatures upward and decreases the thermal hyste...

Physical Review B Structure, Structural phase transitions, Mechanical properties, Defects

Atomic-resolution differential phase contrast STEM on ferroelectric materials: A mean-field approach

M. Campanini, K. Eimre, M. Bon, C. A. Pignedoli, M. D. Rossell, and R. Erni

The ultimate challenge in the investigation of ferroelectric properties lies in the quantitative measurements of their polarization at the unit cell scale. Such investigations are commonly performed using an indirect approach, by measuring the atomic displacements from atomic resolution images. Diff...

Physical Review B Structure, Structural phase transitions, Mechanical properties, Defects

Temperature-induced crystallinity and vibrational properties in samarium orthovanadate

Emin Varghese, Sourabh Kumar, Biswarup Pathak, and Somaditya Sen

The Samarium orthovanadates particles were prepared using the sol-gel method, and the effect of sintering temperature on the crystallinity was studied in detail through x-ray diffraction (XRD) and the Rietveld refinement of the obtained XRD data. Density functional theory (DFT) based calculations we...

Physical Review B Structure, Structural phase transitions, Mechanical properties, Defects

Doubly charged silicon vacancy center, Si-N complexes, and photochromism in N and Si codoped diamond

B. G. Breeze, C. J. Meara, X. X. Wu, C. P. Michaels, R. Gupta, P. L. Diggle, M. W. Dale, B. L. Cann, T. Ardon, U. F. S. D'Haenens-Johansson, I. Friel, M. J. Rayson, P. R. Briddon, J. P. Goss, M. E. Newton, and B. L. Green

Diamond samples containing silicon and nitrogen are shown to be heavily photochromic, with the dominant visible changes due to simultaneous change in total ${\mathrm{SiV}}^{0/−}$ concentration. The photochromism treatment is not capable of creating or destroying SiV defects, and thus we infer the pr...

Physical Review B Structure, Structural phase transitions, Mechanical properties, Defects

Multiple charge density wave states and magnetism in ${\mathrm{NdPt}}_{2}{\mathrm{Si}}_{2}$ against the background of its nonmagnetic analog ${\mathrm{LaPt}}_{2}{\mathrm{Si}}_{2}$

M. Falkowski, P. Doležal, E. Duverger-Nédellec, L.-M. Chamoreau, J. Forté, A. V. Andreev, and L. Havela

Results of structural, magnetic, thermodynamic, and electron transport measurements on single-crystalline ${\mathrm{NdPt}}_{2}{\mathrm{Si}}_{2}$ are reported. Temperature variations of crystal structure show two different charge density wave states. The structure modulation with the propagation vect...

Physical Review B Structure, Structural phase transitions, Mechanical properties, Defects

Scattering cancellation technique for acoustic spinning objects

Mohamed Farhat, Sebastien Guenneau, Andrea Alù, and Ying Wu

The scattering cancellation technique (SCT) has proved to be an effective way to render static objects invisible to electromagnetic and acoustic waves. However, rotating cylindrical or spherical objects possess additional peculiar scattering features that cannot be canceled by regular SCT-based cloa...

Physical Review B Structure, Structural phase transitions, Mechanical properties, Defects

An improved method to model dislocation self-climb

Fengxian Liu, Alan C F Cocks, Simon P A Gill and Edmund Tarleton

Dislocations can provide short circuit diffusion paths for atoms resulting in a dislocation climb motion referred to as self-climb. A variational principle is presented for the analysis of problems in which fast dislocation core diffusion is the dominant mechanism for material redistribution. The linear element based self-climb model, developed in our previous work [1] Liu, Cocks and Tarleton (2020 J. Mech. Phys. Solids 135 103783), is significantly accelerated here, by employing a new finite element discretisation method. The speed-up in computation enables us to use the self-climb model as an effective numerical technique to simulate emergent dislocation behaviour involving both self-climb and glide. The formation of prismatic loops from the break-up of different types of edge dislocation dipoles are investigated based on this new method. We demonstrate that edge dipoles sequentially pinch-off prismatic loops, rather than spontaneously breaking-up into a string of loops...

Modelling and Simulation in Materials Science and Engineering

α ↔ γ phase transformation in iron: comparative study of the influence of the interatomic interaction potential

Jerome Meiser and Herbert M Urbassek

Only few available interatomic interaction potentials implement the α ↔ γ phase transformation in iron by featuring a stable low-temperature bcc and high-temperature fcc lattice structure. Among these are the potentials by Meyer and Entel (1998 Phys. Rev. B 57 5140), by Müller et al (2007 J. Phys.: Condens. Matter 19 326220) and by Lee et al (2012 J. Phys.: Condens. Matter 24 225404). We study how these potentials model the phase transformation during heating and cooling; in order to help initiating the transformation, the simulation volume contains a grain boundary. For the martensitic transformation occurring on cooling an fcc structure, we additionally study two potentials that only implement a stable bcc structure of iron, by Zhou et al (2004 Phys. Rev. B 69 144113) and by Mendelev et al (2003 Philos. Mag. 83 3977). We find that not only the transition temperature ...

Modelling and Simulation in Materials Science and Engineering

Angular dependent interatomic potential for Ti–V system for molecular dynamics simulations

Andrey I Kartamyshev, Alexey G Lipnitskii, Anton O Boev, Ivan V Nelasov, Vyacheslav N Maksimenko, Dmitriy A Aksyonov and Truong Khang Nguyen

An interatomic potential for the Ti–V binary alloy focusing on the evolution of defects, including ones arising as a result of the irradiation process, was constructed within the Lipnitskii–Saveliev approach, which accurately takes into account three-particle interactions and the sum of all multi-particle interactions of a higher order in the framework of the centrally symmetric approximation. In the new potential, Ti–V interactions were fitted to the density functional theory data on a set of model structures with different coordination numbers, including ones with vacancies. The properties used for fitting are accurately reproduced by the present potentials for both pure elements and alloy systems. The potential was tested on the binding energies between Ti atoms and self-point defects in bcc V, elastic moduli, thermal expansion and melting point of some alloys, and diffusion. We obtained qualitative agreement for these properties with available theoretical and experimental da...

Modelling and Simulation in Materials Science and Engineering

A compact plane stress yield function formulation

Sai Hao and Xianghuai Dong

The construction of anisotropic yield function by introducing linear transformations is a common practice with many phenomenological yield criteria. Based on the K 1 − K 2 representation method of principle stresses (represented by Barlat89 yield function), a compact 13-parameter plane stress function is proposed. The new yield function consists of five different linear transformations, and is designed to have a certain symmetry in both the overall structure and the distribution of linear transformation matrix components. The new 13-parameter yield function is applied to predict the yield surfaces (loci), plastic strain rate directions, flow stresses and r -values for both fcc and bcc materials. Compared with the yield functions of Yld2004-18p and CPB06ex2 (both reduce to 14 parameters in symmetric plane stress condition), the new yield function can achieve similar prediction accuracy with fewer parameters.

Modelling and Simulation in Materials Science and Engineering

May 19 2020

Irreversible Qubit-Photon Coupling for the Detection of Itinerant Microwave Photons

Raphaël Lescanne, Samuel Deléglise, Emanuele Albertinale, Ulysse Réglade, Thibault Capelle, Edouard Ivanov, Thibaut Jacqmin, Zaki Leghtas, and Emmanuel Flurin

A new single-photon detector minimizes false positives by ensuring that a qubit switches to its excited state if and only if a photon enters a microwave resonator.

Physical Review X

Rectification in Nonequilibrium Parity Violating Metamaterials

Zhenghan Liao, William T. M. Irvine, and Suriyanarayanan Vaikuntanathan

Mathematical analysis of a model network of linked masses on springs reveals how complex patterns of directed energy motion can arise from random fluctuations.

Physical Review X

Tunable Persistent Random Walk in Swimming Droplets

Adrien Izzet, Pepijn G. Moerman, Preston Gross, Jan Groenewold, Andrew D. Hollingsworth, Jérôme Bibette, and Jasna Brujic

The random motion of oil droplets in water is caused by the flow of surfactants at the interface, a finding that gives rise to a broadly tunable swimming system, akin to microorganisms, and allows us to study their self-organization.

Physical Review X

Realization of a Density-Dependent Peierls Phase in a Synthetic, Spin-Orbit Coupled Rydberg System

Vincent Lienhard, Pascal Scholl, Sebastian Weber, Daniel Barredo, Sylvain de Léséleuc, Rukmani Bai, Nicolai Lang, Michael Fleischhauer, Hans Peter Büchler, Thierry Lahaye, and Antoine Browaeys

An array of highly excited “Rydberg atoms” generates an artificial gauge field, a crucial step for creating quantum simulations that rely on strongly interacting topological matter.

Physical Review X

Solvable Models of Supercooled Liquids in Three Dimensions

Tommaso Rizzo and Thomas Voigtmann

We introduce a supercooled liquid model and obtain parameter-free quantitative predictions that are in excellent agreement with numerical simulations, notably in the hard low-temperature region characterized by strong deviations from mode-coupling-theory behavior. The model is the Fredrickson-Anders...

Physical Review Letters

Strumming a Single Chemical Bond

Alfred J. Weymouth, Elisabeth Riegel, Oliver Gretz, and Franz J. Giessibl

Atomic force microscopy and scanning tunneling microscopy can image the internal structure of molecules adsorbed on surfaces. One reliable method is to terminate the tip with a nonreactive adsorbate, often a single CO molecule, and to collect data at a close distance where Pauli repulsion plays a st...

Physical Review Letters

Optical enhancement of dielectric permittivity in reduced lanthanum aluminate

Takayuki Nagai, Akihide Kuwabara, Yu Kumagai, Ichiro Terasaki, and Hiroki Taniguchi

When light is absorbed in solids, electrical conductivity is usually enhanced through generation of photodoped conductive carriers, known as photoconduction. Here we show UV-light absorption restrains photoconduction, but markedly enhances dielectric permittivity in a ceramic sample of $\mathrm{LaAl...

Physical Review B Structure, Structural phase transitions, Mechanical properties, Defects

Coherent acoustic phonons generated by ultrashort terahertz pulses in nanofilms of metals and topological insulators

A. Levchuk, B. Wilk, G. Vaudel, F. Labbé, B. Arnaud, K. Balin, J. Szade, P. Ruello, and V. Juvé

We report the generation of coherent acoustic phonons in materials with terahertz ultrashort pulses. This is demonstrated in metals and topological insulators by exciting an acoustic eigenmode in nanometric-sized thin films. The efficiency of the coupling is quadratic in the terahertz electric field...

Physical Review B Structure, Structural phase transitions, Mechanical properties, Defects

Pressure-induced decomposition of binary lanthanum intermetallic compounds

Xin Yang, Hefei Li, Hanyu Liu, Hui Wang, Yansun Yao, and Yu Xie

We present a comprehensive study on structural and electronic properties of lanthanum intermetallic compounds (${M}_{x}{\mathrm{La}}_{y}$, $M=\text{Be}$, Mg, Al, Ga, In, Tl, Pb, and Bi) under high pressure. By using a swarm intelligence structure search method combined with first-principles calculat...

Physical Review B Structure, Structural phase transitions, Mechanical properties, Defects

Spontaneous ferroelectric order in lead-free relaxor $\mathrm{N}{\mathrm{a}}_{1/2}\mathrm{B}{\mathrm{i}}_{1/2}\mathrm{Ti}{\mathrm{O}}_{3}$-based composites

Lalitha K. V., Manuel Hinterstein, Kai-Yang Lee, Tiannan Yang, Long-Qing Chen, Pedro B. Groszewicz, Jurij Koruza, and Jürgen Rödel

Short-range ordered polar nanoregions are key to the giant electromechanical properties exhibited by relaxor ferroelectrics. Stabilization of the long-range ferroelectric order in relaxor systems has typically been achieved by applying external fields. In this work, spontaneous (zero-field) ferroele...

Physical Review B Structure, Structural phase transitions, Mechanical properties, Defects

High-pressure structural systematics in samarium up to 222 GPa

S. E. Finnegan, E. J. Pace, C. V. Storm, M. I. McMahon, S. G. MacLeod, H.-P. Liermann, and K. Glazyrin

Angle-dispersive x-ray powder diffraction experiments have been performed on samarium metal up to 222 GPa. Up to 50 GPa we observe the Sm type ($hR9$) $→$ dhcp ($hP4$) $→$ fcc ($cF4$) $→$ distorted fcc ($hR24$) $→\phantom{\rule{4pt}{0ex}}hP3$ transition sequence reported previously. The structure of...

Physical Review B Structure, Structural phase transitions, Mechanical properties, Defects

Thermodynamic stabilization of $γ\text{−}\mathrm{U}−\mathrm{Mo}$ alloys: Effect of Mo content and temperature

Aloïs Castellano, François Bottin, Boris Dorado, and Johann Bouchet

The $γ\text{−}\mathrm{U}−\mathrm{Mo}$ alloys have been studied by means of ab initio molecular-dynamic simulations at 900 K as a function of the Mo concentration (0%, 25%, 50%, 75%, and 100%). Using the temperature-dependent effective potential method with the symmetry-imposed force constant extensi...

Physical Review B Structure, Structural phase transitions, Mechanical properties, Defects

Extended flat band, entanglement, and topological properties in a Creutz ladder

Yoshihito Kuno

In this work, we study the entanglement and topological properties of an extended flat-band Creutz ladder by considering a compacted localized state (CLS). Based on the CLS picture, we find a multiple flat-band extension from the conventional two flat-band Creutz ladder. A simple vertical interchain...

Physical Review B Structure, Structural phase transitions, Mechanical properties, Defects

Structural and thermal transport properties of ferroelectric domain walls in GeTe from first principles

Đorđe Dangić, Éamonn D. Murray, Stephen Fahy, and Ivana Savić

Ferroelectric domain walls are boundaries between regions with different polarization orientations in a ferroelectric material. Using first-principles calculations, we characterize all different types of domain walls forming on ($11\overline{1}$), (111), and ($1\overline{1}0$) crystallographic plane...

Physical Review B Structure, Structural phase transitions, Mechanical properties, Defects

First-principles study of the low-temperature charge density wave phase in the quasi-one-dimensional Weyl chiral compound $({\mathrm{TaSe}}_{4}{)}_{2}\mathrm{I}$

Yang Zhang, Ling-Fang Lin, Adriana Moreo, Shuai Dong, and Elbio Dagotto

Using ab initio density functional theory, we study the lattice phase transition of quasi-one-dimensional $({\mathrm{TaSe}}_{4}{)}_{2}\mathrm{I}$. In the undistorted state, the strongly anisotropic semimetal band structure presents two nonequivalent Weyl points. In previous efforts, two possible Ta-...

Physical Review B Structure, Structural phase transitions, Mechanical properties, Defects

Mutual dependence of oxygen and vacancy diffusion in bcc Fe and dilute iron alloys

X. Wang, J. Faßbender, and M. Posselt

A combination of density functional theory (DFT) and an efficient calculation method based on atomistic kinetic Monte Carlo simulations (AKMC) is used to investigate the interdependence of oxygen (O) and vacancy (v) diffusion in bcc Fe and in dilute iron alloys with the substitutional atoms Y and Ti...

Physical Review B Structure, Structural phase transitions, Mechanical properties, Defects

Angular dependence of fast-electron scattering from materials

Juri Barthel, Mauricio Cattaneo, Budhika G. Mendis, Scott D. Findlay, and Leslie J. Allen

Angular resolved scanning transmission electron microscopy is an important tool for investigating the properties of materials. However, several recent studies have observed appreciable discrepancies in the angular scattering distribution between experiment and theory. In this paper we discuss a gene...

Physical Review B Structure, Structural phase transitions, Mechanical properties, Defects

Optical properties of shock-compressed diamond up to 550 GPa

Kento Katagiri, Norimasa Ozaki, Kohei Miyanishi, Nobuki Kamimura, Yuhei Umeda, Takayoshi Sano, Toshimori Sekine, and Ryosuke Kodama

A series of shock wave experiments were conducted to measure the optical properties of single-crystal diamond $〈100〉$ in the pressure regime between 60 and 550 GPa. The results show that the transparency limit of diamond at 532 nm is $∼170\phantom{\rule{0.16em}{0ex}}\mathrm{GPa}$. When the applied p...

Physical Review B Structure, Structural phase transitions, Mechanical properties, Defects

High spatial resolution studies of phase transitions within organic aperiodic crystals

Céline Mariette, Laurent Guérin, Philippe Rabiller, Christophe Odin, Mariana Verezhak, Alexei Bosak, Philippe Bourges, Claude Ecolivet, and Bertrand Toudic

The understanding of the symmetry breakings within crystals that are aperiodic by construction is actually very limited. Quasicrystals and incommensurate composite crystals may potentially allow such studies. We focus on the phase transitions of the aperiodic $n$-nonadecane/urea which recovers a tra...

Physical Review B Structure, Structural phase transitions, Mechanical properties, Defects

Carbon vacancy-related centers in $3C$-silicon carbide: Negative-$U$ properties and structural transformation

H. J. von Bardeleben, E. Rauls, and U. Gerstmann

Combining electron paramagnetic resonance (EPR) spectroscopy and first-principles density functional theory calculations we have identified the carbon monovacancy center and a second carbon vacancy-related defect, the carbon vacancy–carbon antisite defect in $3C$-SiC. In close analogy to the vacancy...

Physical Review B Structure, Structural phase transitions, Mechanical properties, Defects

Origin of the persistence of soft modes in metallic ferroelectrics

Zegnet Yimer and Huaxiang Fu

Metallicity and ferroelectriclike polar distortion are mutually noncompatible, and their coexistence in the same system is an intriguing subject of fundamental interest in the field of structure phase transition. However, it is unclear what mechanism may extend the limit of metallicity that allows p...

Physical Review B Structure, Structural phase transitions, Mechanical properties, Defects

Shock compression response of diamond single crystals at multimegabar stresses

J. M. Winey, M. D. Knudson, and Y. M. Gupta

Shock compressed diamond response at multimegabar stresses—of fundamental interest to high pressure science and relevant for high energy density experiments related to inertial confinement fusion—is often assumed to be hydrodynamic. To examine this assumption, plate impact experiments were conducted...

Physical Review B Structure, Structural phase transitions, Mechanical properties, Defects

Numerical microstructure model of NiTi wire reconstructed from 3D-XRD data

L Heller, I Karafítov́, L Petrich, Z Pawlas, P Shayanfard, V Beneš, V Schmidt and P Šittner

In this paper, the grain microstructure and strain partitioning in a polycrystalline NiTi wire subjected to tensile loading was reconstructed from an experimental 3D-XRD dataset. The reconstruction of a volume containing more than 8000 stressed grains involved optimization with respect to both the geometrical features and material elastic properties. The geometrical features of the microstructure were reconstructed using Laguerre tessellations based on the experimental 3D-XRD dataset. Two different algorithms fitting Laguerre tessellations were applied in order to assess the sensitivity of the reconstruction to the choice of the algorithm. The material properties in terms of elastic anisotropy were refined from an initial published value to minimize the mismatch between experiment and simulation using an optimization algorithm based on linear elasticity simulations. As a result of this, we constructed a numerical microstructure model that statistically matches the experimentally...

Modelling and Simulation in Materials Science and Engineering

Emergence of directionally-anisotropic mobility in a faceted Ʃ11 ⟨ 110 ⟩ tilt grain boundary in Cu

Megan J McCarthy and Timothy J Rupert

Faceted grain boundaries, where grain boundary area is increased in the name of producing low-energy segments, can exhibit new and unexpected migration trends. For example, several faceted Ʃ3 boundaries have demonstrated anti-thermal and thermally damped mobility. Ʃ11 ⟨110⟩ tilt boundaries represent another promising but relatively unexplored set of interfaces, with a (113) low-energy plane that can lead to faceting. In this study, molecular dynamics simulations are used to study grain boundary migration of an asymmetric Ʃ11 ⟨110⟩ grain boundary in two face centered cubic metals. Mobility of this boundary in Cu is strongly dependent on the direction of the applied driving force. The mobility anisotropy generally becomes smaller, but does not disappear completely, as temperature is increased. In contrast, the same boundary in Al demonstrates similar mobilities in either direction, illustrating that the anisotropic mobility phenomenon is material-dependent. Finally, relationships ...

Modelling and Simulation in Materials Science and Engineering

Quantification of 3D spatial correlations between state variables and distances to the grain boundary network in full-field crystal plasticity spectral method simulations

Markus Kühbach and Franz Roters

Deformation microstructure heterogeneities play a pivotal role during dislocation patterning and interface network restructuring. Thereby, they affect indirectly how the microstructure recrystallizes. Given this relevance, it has become common practice to study the evolution of deformation microstructure heterogeneities with 3D experiments and full-field crystal plasticity computer simulations including tools such as the spectral method. Quantifying material point to grain or phase boundary distances, though, is a practical challenge with spectral method crystal plasticity models because these discretize the material volume rather than mesh explicitly the grain and phase boundary interface network. This limitation calls for specific data post-processing methods to quantify the spatial correlations between state variable values at each material point and the points’ corresponding distance to the closest grain or phase boundary. This work contributes to the development of advanced...

Modelling and Simulation in Materials Science and Engineering

Investigation of partial dislocations fluctuations yields dislocation core parameters

Pierre-Antoine Geslin and David Rodney

In this work, we investigate the thermal fluctuations of dissociated dislocations in face-centered cubic metals. We first derive an analytical expression of the energy of perturbed interacting partial dislocations. Combining this expression with the equipartition theorem yields a prediction for the thermal fluctuations of interacting partials. Comparing this prediction with atomistic calculations in nickel allows to extract the core energy of the partials at finite temperature and as function of their orientation. We also show how to use these values to parameterize the energetics of perfect dislocations and clarify the scope of validity of representing dissociated dislocations as perfect dislocation lines, an approximation customarily made in dislocation dynamics approaches.

Modelling and Simulation in Materials Science and Engineering

An implementation of the phase-field model based on coupled thermomechanical finite element solvers for large-strain twinning, explicit dynamic fracture and the classical Stefan problem

Milovan Zecevic, M J Cawkwell, K J Ramos and D J Luscher

The implementation of a phase-field model in finite elements usually requires significant expertise and involves the development of a user element with additional degrees of freedom. An alternative implementation of the phase-field model within a thermo-mechanical finite element simulation package was presented in (Cho et al 2012 Int. J. Solids Struct. 49 1973–1992), where the phase-field variable is treated as the temperature degree of freedom. However, this approach has only been used for small strain phase-field modelling of martensitic transformations and quasistatic phase-field modelling of fracture. In this work, we present a phase-field finite element implementation via the temperature degree of freedom for several additional cases from the literature: (i) the large-strain phase-field description of deformation twinning presented in (Clayton and Knap 2011 Physica D 240 841–858), (ii) phase-field description of brittle fracture with inert...

Modelling and Simulation in Materials Science and Engineering

May 07 2020

Robust Ferromagnetism in Highly Strained ${\mathrm{SrCoO}}_{3}$ Thin Films

Yujia Wang, Qing He, Wenmei Ming, Mao-Hua Du, Nianpeng Lu, Clodomiro Cafolla, Jun Fujioka, Qinghua Zhang, Ding Zhang, Shengchun Shen, Yingjie Lyu, Alpha T. N’Diaye, Elke Arenholz, Lin Gu, Cewen Nan, Yoshinori Tokura, Satoshi Okamoto, and Pu Yu

A new and unexpected ferromagnetic ground state emerges in highly strained thin films of a transition-metal oxide, shedding new light on electronic and magnetic properties that could be manipulated via strain engineering.

Physical Review X

Origin of Plasticity in Nanostructured Silicon

Zhidan Zeng, Qiaoshi Zeng, Mingyuan Ge, Bin Chen, Hongbo Lou, Xiehang Chen, Jinyuan Yan, Wenge Yang, Ho-kwang Mao, Deren Yang, and Wendy L. Mao

The mechanism of plasticity in nanostructured Si has been intensively studied over the past decade but still remains elusive. Here, we used in situ high-pressure radial x-ray diffraction to simultaneously monitor the deformation and structural evolution of a large number of randomly oriented Si nano...

Physical Review Letters

Unsupervised Manifold Clustering of Topological Phononics

Yang Long, Jie Ren, and Hong Chen

Classification of topological phononics is challenging due to the lack of universal topological invariants and the randomness of structure patterns. Here, we show the unsupervised manifold learning for clustering topological phononics without any a priori knowledge, neither topological invariants no...

Physical Review Letters

Control of strong-field ionization in ferroelectric lithium niobate: Role of the spontaneous polarization

Vincent Wanie, Tian-Jiao Shao, Philippe Lassonde, Heide Ibrahim, Jude Deschamps, Jia-Qi Liu, Fabian Ambriz Vargas, François Vidal, Andreas Ruediger, Francesca Calegari, Xue-Bin Bian, and François Légaré

We report the control of tunnel ionization in lithium niobate (${\mathrm{LiNbO}}_{3}$) using phase-controlled two-color laser fields. Through a macroscopic observable of high contrast, we disclose the crucial contribution of the microscopic spontaneous polarization of the ferroelectric material to t...

Physical Review B Structure, Structural phase transitions, Mechanical properties, Defects

Synthetic spin-orbit coupling mediated by a bosonic environment

Mikhail Maslov, Mikhail Lemeshko, and Enderalp Yakaboylu

We study a mobile quantum impurity, possessing internal rotational degrees of freedom, confined to a ring in the presence of a many-particle bosonic bath. By considering the recently introduced rotating polaron problem, we define the Hamiltonian and examine the energy spectrum. The weak-coupling reg...

Physical Review B Structure, Structural phase transitions, Mechanical properties, Defects

Optical signatures of phase transitions and structural modulation in elemental tellurium under pressure

Diego Rodriguez, Alexander A. Tsirlin, Tobias Biesner, Teppei Ueno, Takeshi Takahashi, Kaya Kobayashi, Martin Dressel, and Ece Uykur

A room-temperature infrared spectroscopy study of elemental tellurium at pressures up to 8.44 GPa in the energy range $0.015–2$ eV is reported. Optical signatures of the high-pressure polymorphs are investigated and compared to the results of density-functional band-structure calculations. A Drude p...

Physical Review B Structure, Structural phase transitions, Mechanical properties, Defects

Possible role of grain-boundary and dislocation structure for the magnetic-flux trapping behavior of niobium: A first-principles study

P. Garg, C. Muhich, L. D. Cooley, T. R. Bieler, and K. N. Solanki

First-principles methods were used to understand magnetic flux trapping at vacancies, dislocations, and grain boundaries in high-purity superconducting niobium. Full-potential linear augmented plane-wave methods were applied in progressively greater complexity, starting at simple vacancies and exten...

Physical Review B Structure, Structural phase transitions, Mechanical properties, Defects

May 06 2020

Optical Nonlocality in Polar Dielectrics

Christopher R. Gubbin and Simone De Liberato

By including nonlocal effects, a new theory provides an accurate description of the optical properties of nanostructures made of polar dielectrics—crystal semiconductors formed from polar molecules.

Physical Review X

Temperature dependence of surface and grain boundary energies from first principles

Daniel Scheiber, Oliver Renk, Maxim Popov, and Lorenz Romaner

In this study we systematically study the temperature dependence of interface energies in W using first principles. To that purpose, we compute interface free energies and consider different contributions, i.e., from lattice expansion, vibrational contribution from harmonic and quasiharmonic approxi...

Physical Review B Structure, Structural phase transitions, Mechanical properties, Defects

Enhanced transient negative capacitance during inhomogeneous ferroelectric switching

Bin Xu, Sergey Prosandeev, Charles Paillard, and L. Bellaiche

The reversal of polarization in a ferroelectric material involves overcoming an energy barrier, and has been previously proposed and found to yield transient negative capacitance (NC) in the intermediate states of the switching process. Homogeneous switching was assumed to interpret the experimental...

Physical Review B Structure, Structural phase transitions, Mechanical properties, Defects

Theory of finite-temperature two-dimensional structural transformations in group-IV monochalcogenide monolayers

John W. Villanova, Pradeep Kumar, and Salvador Barraza-Lopez

One account of two-dimensional (2D) structural transformations in 2D ferroelectrics predicts an evolution from a structure with ${\mathrm{Pnm}2}_{1}$ symmetry into a structure with square P4/nmm symmetry and is consistent with experimental evidence, while another argues for a transformation into a s...

Physical Review B Structure, Structural phase transitions, Mechanical properties, Defects

Computational discovery of a dynamically stable cubic ${\mathrm{SH}}_{3}$-like high-temperature superconductor at 100 GPa via ${\mathrm{CH}}_{4}$ intercalation

Ying Sun, Yifan Tian, Bowen Jiang, Xue Li, Hefei Li, Toshiaki Iitaka, Xin Zhong, and Yu Xie

The 203 K superconductivity of ${\mathrm{SH}}_{3}$ stimulates enormous interest in searching for high-temperature superconductors in compressed hydrides. While several hydrides show high-temperature superconductivity ($>180\phantom{\rule{0.16em}{0ex}}\mathrm{K}$) at extremely high pressure, it is...

Physical Review B Structure, Structural phase transitions, Mechanical properties, Defects

Chemical trend of a Cu impurity in Zn chalcogenides

Yang Yang, Peng Zhang, Jingxiu Yang, and Su-Huai Wei

Cu is usually considered as an effective dopant to introduce shallow acceptors in Zn chalcogenides because it is on the left-hand side of Zn in the Periodic Table. Here, using first-principles calculations based on the hybrid functional with spin polarization, we show that contrary to the common exp...

Physical Review B Structure, Structural phase transitions, Mechanical properties, Defects

Fourier spectral methods for phase field fracture modelling of CMCs

B Pankowski

Numerical homogenization of multiphase brittle materials, such as ceramic matrix composites is obviously a computationally intensive task. Common approach involving multiscale finite element models remains quite limited to scientific applications instead of being a reasonable alternative for analytical constitutive models. Despite the exponential growth of computational resources (known as Moore’s law) numerical complexity of the underlying algorithms is simply too high to ensure proper scaling to millions of elements. One of the approaches in-between continuous and discrete mechanics is the use of fast Fourier transform (FFT). The aim of this paper is to extend FFT-based methodology beyond its usual elastic regime, using mathematical formalism developed earlier for FE by means of variational principles. Governing equations are formulated in the frequency domain and solved iteratively on a parallel system. Well-known computational specifics of the discrete FFT algorithm itself p...

Modelling and Simulation in Materials Science and Engineering

Theoretical study of post-shock stress relaxation and shock wave deformation around a pore in single and poly-crystalline α-RDX

Yao Long and Jun Chen

The mechanical properties and shock dynamics of α-hexahydro-1,3,5-trinitro-1,3,5-triazine (α-RDX) are simulated by molecular dynamics (MD). Based on the simulation results, the equation of state, Hugoniot curve and isoentropic curve for α-RDX are calculated, and the microscopic structure of shock wave is investigated, including the wave profile and the shock front deformation. First, we prove that the shock wave profile is determined by the viscoelastic equation of α-RDX, and develop a method to inverse the viscoelastic coefficients from the velocity profile calculated by MD. Two stress relaxation mechanisms are obtained: the boundary scattering and molecular rotation. The boundary scattering mechanism shows that the damping time of stress relaxation is determined by the particle size of polycrystal. Second, we find that the pore collapse induces rarefaction wave after the shock front. The rarefaction wave function is evaluated by using the Riemann invariant method, and the shoc...

Modelling and Simulation in Materials Science and Engineering

Impulsive generation of 〈100〉 dislocation loops in BCC iron

A I Bertoni, O R Deluigi, G J Dos Santos, M Perez Díaz and E M Bringa

The conditions for the formation of 〈100〉 dislocation loops in body-centered cubic (BCC) iron were investigated via molecular dynamics simulations using a simplified model intended to mimic conditions in high energy collision cascades, focusing on the possible coherent displacement of atoms at the boundary of a subcascade. We report on the formation of 〈100〉 dislocation loops due to the fast displacement of a few hundred atoms with a coherent acceleration, in agreement with previous results for much larger cascade simulations. We analyze in detail the resulting atomic velocities and pressures, and find that they cannot be described within the usual formalism for a shock regime, since the pressure pulse only lasts less than 1 ps and does not match expected values from a Hugoniot shock. Our simulations include two interatomic potentials: Mendelev, which is extensively used for radiation damage simulations, and Ackland, which has been used for shock simulations because it can repro...

Modelling and Simulation in Materials Science and Engineering

May 01 2020

Observation of Quantized Exciton Energies in Monolayer ${\mathrm{WSe}}_{2}$ under a Strong Magnetic Field

Tianmeng Wang, Zhipeng Li, Zhengguang Lu, Yunmei Li, Shengnan Miao, Zhen Lian, Yuze Meng, Mark Blei, Takashi Taniguchi, Kenji Watanabe, Sefaattin Tongay, Wang Yao, Dmitry Smirnov, Chuanwei Zhang, and Su-Fei Shi

Experiments show for the first time the quantization of exciton energies in a 2D semiconductor exposed to a high magnetic field, setting the stage for explorations of quantized excitons in the presence of strong Coulomb interactions.

Physical Review X

Neural Canonical Transformation with Symplectic Flows

Shuo-Hui Li, Chen-Xiao Dong, Linfeng Zhang, and Lei Wang

A modern machine learning known as normalizing flow can automate cumbersome canonical transformations of Hamiltonian equations, thereby opening up this time-honored technique for studying dynamics to a wide array of complex systems.

Physical Review X

Photonic-Crystal Josephson Traveling-Wave Parametric Amplifier

Luca Planat, Arpit Ranadive, Rémy Dassonneville, Javier Puertas Martínez, Sébastien Léger, Cécile Naud, Olivier Buisson, Wiebke Hasch-Guichard, Denis M. Basko, and Nicolas Roch

A new solution to the phase-matching problem common to so-called traveling-wave parametric amplifiers is achieved with a simple design that’s easy to fabricate.

Physical Review X

Complex Spacing Ratios: A Signature of Dissipative Quantum Chaos

Lucas Sá, Pedro Ribeiro, and Tomaž Prosen

Mathematical tools for distinguishing open quantum systems that are chaotic from those that are exactly solvable fill an important gap in understanding dissipation and decoherence in scenarios relevant to quantum-based technologies.

Physical Review X

Controlled Introduction of Defects to Delafossite Metals by Electron Irradiation

V. Sunko, P. H. McGuinness, C. S. Chang, E. Zhakina, S. Khim, C. E. Dreyer, M. Konczykowski, H. Borrmann, P. J. W. Moll, M. König, D. A. Muller, and A. P. Mackenzie

Experiments reveal that the high conductivity of delafossite oxide materials arises from an extreme degree of purity in their naturally grown crystal structures, a finding that aids the quest for ever-better conductors.

Physical Review X

Spectroscopic and Structural Probing of Excited-State Molecular Dynamics with Time-Resolved Photoelectron Spectroscopy and Ultrafast Electron Diffraction

Yusong Liu, Spencer L. Horton, Jie Yang, J. Pedro F. Nunes, Xiaozhe Shen, Thomas J. A. Wolf, Ruaridh Forbes, Chuan Cheng, Bryan Moore, Martin Centurion, Kareem Hegazy, Renkai Li, Ming-Fu Lin, Albert Stolow, Paul Hockett, Tamás Rozgonyi, Philipp Marquetand, Xijie Wang, and Thomas Weinacht

The combination of computer simulations and two powerful experimental methods for following molecular change on femtosecond timescales offers an unprecedented view of how a photoexcited molecule breaks apart.

Physical Review X

Thermally Enhanced Electro-osmosis to Control Foam Stability

Oriane Bonhomme, Li Peng, and Anne-Laure Biance

Electric fields can control the stability of liquid foams, a versatile material used in many industrial applications that is otherwise difficult to stabilize or destabilize on demand.

Physical Review X

Light-Driven Raman Coherence as a Nonthermal Route to Ultrafast Topology Switching in a Dirac Semimetal

C. Vaswani, L.-L. Wang, D. H. Mudiyanselage, Q. Li, P. M. Lozano, G. D. Gu, D. Cheng, B. Song, L. Luo, R. H. J. Kim, C. Huang, Z. Liu, M. Mootz, I. E. Perakis, Y. Yao, K. M. Ho, and J. Wang

A light-induced phase transition in a Dirac material offers insight into how these materials respond to periodic driving (that is, quantum back-and-forth motion), information necessary for topology-based quantum computation and topological transistors.

Physical Review X

Quantum Logic Spectroscopy with Ions in Thermal Motion

D. Kienzler, Y. Wan, S. D. Erickson, J. J. Wu, A. C. Wilson, D. J. Wineland, and D. Leibfried

An enhanced version of quantum logic spectroscopy, used to map absorption and emission from single atoms, tolerates some ion motion and entangles several ions for improved sensitivity.

Physical Review X

Interacting Polaron-Polaritons

Li Bing Tan, Ovidiu Cotlet, Andrea Bergschneider, Richard Schmidt, Patrick Back, Yuya Shimazaki, Martin Kroner, and Ataç İmamoğlu

Photons in certain materials can form massive, strongly interacting quasiparticles, giving rise to nonlinear effects that could be useful in quantum optics.

Physical Review X

Field-Angle-Resolved Magnetic Excitations as a Probe of Hidden-Order Symmetry in ${\mathrm{CeB}}_{6}$

P. Y. Portnichenko, A. Akbari, S. E. Nikitin, A. S. Cameron, A. V. Dukhnenko, V. B. Filipov, N. Yu. Shitsevalova, P. Čermák, I. Radelytskyi, A. Schneidewind, J. Ollivier, A. Podlesnyak, Z. Huesges, J. Xu, A. Ivanov, Y. Sidis, S. Petit, J.-M. Mignot, P. Thalmeier, and D. S. Inosov

A novel approach to analyzing neutron-scattering data offers a new way to probe magnetic order arising from higher-order electron multipoles.

Physical Review X

Learning Force Fields from Stochastic Trajectories

Anna Frishman and Pierre Ronceray

Reconstructing a stochastic dynamical model from single noisy trajectories of complex Brownian systems is made possible by an efficient force inference technique.

Physical Review X

Repetitive Quantum Nondemolition Measurement and Soft Decoding of a Silicon Spin Qubit

Xiao Xue, Benjamin D’Anjou, Thomas F. Watson, Daniel R. Ward, Donald E. Savage, Max G. Lagally, Mark Friesen, Susan N. Coppersmith, Mark A. Eriksson, William A. Coish, and Lieven M. K. Vandersypen

An experiment measures an individual electron spin with high fidelity and without demolishing it, thus setting the stage for robust quantum error correction with spin qubits in silicon.

Physical Review X

3D Spatial Exploration by E. coli Echoes Motor Temporal Variability

Nuris Figueroa-Morales, Rodrigo Soto, Gaspard Junot, Thierry Darnige, Carine Douarche, Vincent A. Martinez, Anke Lindner, and Éric Clément

Experiments show that bacteria constantly alter their exploration states—frequent directional changes and persistent swimming—which could provide insight into the onset of infections and the dynamics of microbial communities.

Physical Review X

Absence of a Dissipative Quantum Phase Transition in Josephson Junctions

A. Murani, N. Bourlet, H. le Sueur, F. Portier, C. Altimiras, D. Esteve, H. Grabert, J. Stockburger, J. Ankerhold, and P. Joyez

Experiments show that, contrary to long-held predictions, a Josephson junction in series with a large enough resistance does not become insulating at low temperature, thus forcing a reanalysis of quantum phase transitions in these and similar systems.

Physical Review X

Equation of State of Liquid Iron under Extreme Conditions

Yasuhiro Kuwayama, Guillaume Morard, Yoichi Nakajima, Kei Hirose, Alfred Q. R. Baron, Saori I. Kawaguchi, Taku Tsuchiya, Daisuke Ishikawa, Naohisa Hirao, and Yasuo Ohishi

The density of liquid iron is measured experimentally at conditions that match those inside Earth.

Physical Review Letters

Fully Coupled Two-Fluid Dynamics in Superfluid $^{4}\mathrm{He}$: Anomalous Anisotropic Velocity Fluctuations in Counterflow

Satoshi Yui, Hiromichi Kobayashi, Makoto Tsubota, and Wei Guo

We investigate the thermal counterflow of the superfluid $^{4}\mathrm{He}$ by numerically simulating three-dimensional fully coupled dynamics of the two fluids, namely quantized vortices and a normal fluid. We analyze the velocity fluctuations of the laminar normal fluid arising from the mutual fric...

Physical Review Letters

Many-Body Dynamical Localization in a Kicked Lieb-Liniger Gas

Colin Rylands, Efim B. Rozenbaum, Victor Galitski, and Robert Konik

The kicked rotor system is a textbook example of how classical and quantum dynamics can drastically differ. The energy of a classical particle confined to a ring and kicked periodically will increase linearly in time whereas in the quantum version the energy saturates after a finite number of kicks....

Physical Review Letters

Lognormal Distribution of Local Strain: A Universal Law of Plastic Deformation in Material

Ao Tang, Haiting Liu, Guisen Liu, Yong Zhong, Li Wang, Qi Lu, Jeff Wang, and Yao Shen

Given the infinite diversity of microstructural inhomogeneity, the variation in spatial distribution of local strain could be infinite. However, this study finds that the statistical distribution of local strain universally follows a lognormal distribution irrespective of phase content and deformati...

Physical Review Letters

Structural Ordering in Liquid Gallium under Extreme Conditions

James W. E. Drewitt, Francesco Turci, Benedict J. Heinen, Simon G. Macleod, Fei Qin, Annette K. Kleppe, and Oliver T. Lord

The atomic-scale structure, melting curve, and equation of state of liquid gallium has been measured to high pressure ($p$) and high temperature ($T$) up to 26 GPa and 900 K by in situ synchrotron x-ray diffraction. Ab initio molecular dynamics simulations up to 33.4 GPa and 1000 K are in excellent ...

Physical Review Letters

Anharmonic Eigenvectors and Acoustic Phonon Disappearance in Quantum Paraelectric ${\mathrm{SrTiO}}_{3}$

Xing He, Dipanshu Bansal, Barry Winn, Songxue Chi, Lynn Boatner, and Olivier Delaire

Pronounced anomalies in the ${\mathrm{SrTiO}}_{3}$ dynamical structure factor, $S(\mathbf{Q},E)$, including the disappearance of acoustic phonon branches at low temperatures, were uncovered with inelastic neutron scattering (INS) and simulations. The striking effect reflects anharmonic couplings bet...

Physical Review Letters

Performance of the standard exchange-correlation functionals in predicting melting properties fully from first principles: Application to Al and magnetic Ni

Li-Fang Zhu, Fritz Körmann, Andrei V. Ruban, Jörg Neugebauer, and Blazej Grabowski

We apply the efficient two-optimized references thermodynamic integration using Langevin dynamics method [Phys. Rev. B 96, 224202 (2017)] to calculate highly accurate melting properties of Al and magnetic Ni from first principles. For Ni we carefully investigate the impact of magnetism on the liquid...

Physical Review B Structure, Structural phase transitions, Mechanical properties, Defects

Local vibrational modes of Si vacancy spin qubits in SiC

Z. Shang, A. Hashemi, Y. Berencén, H.-P. Komsa, P. Erhart, S. Zhou, M. Helm, A. V. Krasheninnikov, and G. V. Astakhov

Silicon carbide is a very promising platform for quantum applications because of the extraordinary spin and optical properties of point defects in this technologically friendly material. These properties are strongly influenced by crystal vibrations, but the exact relationship between them and the b...

Physical Review B Structure, Structural phase transitions, Mechanical properties, Defects

Prediction of a novel high-pressure phase of hydrogen peroxide

Xinyu Zhang, Wenbo Zhao, Siyu Liu, Lihua Yang, Qing Guo, Jian Lv, and Yanchao Wang

The binary H-O system almost exclusively exists in the form of water ice with stoichiometry of ${\mathrm{H}}_{2}\mathrm{O}$ in a wide range of pressure (∼5 TPa) that is one of the most abundant substances in the solar system. Hydrogen peroxide (${\mathrm{H}}_{2}{\mathrm{O}}_{2}$) is only metastable ...

Physical Review B Structure, Structural phase transitions, Mechanical properties, Defects

${\mathrm{Bi}}_{2}{\mathrm{W}}_{2}{\mathrm{O}}_{9}$: A potentially antiferroelectric Aurivillius phase

Hania Djani, Emma E. McCabe, W. Zhang, P. S. Halasyamani, A. Feteira, Jordan Bieder, Eric Bousquet, and Philippe Ghosez

Ferroelectric tungsten-based Aurivillius oxides are naturally stable superlattice structures, in which $A$-site deficient perovskite blocks ${[{\mathrm{W}}_{n}{\mathrm{O}}_{3n+1}]}^{−2}$ ($n=1,2,3,⋯$) interleave with fluorite-like bismuth oxide layers ${[{\mathrm{Bi}}_{2}{\mathrm{O}}_{2}]}^{+2}$ alo...

Physical Review B Structure, Structural phase transitions, Mechanical properties, Defects

Experimental characterization of spin-$\frac{3}{2}$ silicon vacancy centers in $6H$-SiC

Harpreet Singh, Andrei N. Anisimov, Sergei S. Nagalyuk, Eugenii N. Mokhov, Pavel G. Baranov, and Dieter Suter

Silicon carbide (SiC) hosts many interesting defects that can potentially serve as qubits for a range of advanced quantum technologies. Some of them have very interesting properties, making them potentially useful, e.g., as interfaces between stationary and flying qubits. Here we present a detailed ...

Physical Review B Structure, Structural phase transitions, Mechanical properties, Defects

Gauging defects in quantum spin systems: A case study

Jacob C. Bridgeman, Alexander Hahn, Tobias J. Osborne, and Ramona Wolf

The goal of this work is to build a dynamical theory of defects for quantum spin systems. This is done by explicitly giving an exhaustive case study of a one-dimensional spin chain with $\mathbf{Vec}(\mathbb{Z}/2\mathbb{Z})$ fusion rules, which can easily be extended to more general settings. A kine...

Physical Review B Structure, Structural phase transitions, Mechanical properties, Defects

Atomic-scale origin of ultrahigh piezoelectricity in samarium-doped PMN-PT ceramics

Chunchun Li, Bin Xu, Dabin Lin, Shujun Zhang, Laurent Bellaiche, Thomas R. Shrout, and Fei Li

Designing high-performance piezoelectric materials based on atomic-scale calculations is highly desired in recent years, following the understanding of the structure-property relationship of state-of-the-art piezoelectric materials. Previous mesoscale simulations showed that local structural heterog...

Physical Review B Structure, Structural phase transitions, Mechanical properties, Defects

Structural and electronic properties of two-dimensional freestanding $\mathrm{BaTi}{\mathrm{O}}_{3}/\mathrm{SrTi}{\mathrm{O}}_{3}$ heterostructures

Fanhao Jia, Shaowen Xu, Guodong Zhao, Chao Liu, and Wei Ren

The successful preparation of the freestanding perovskite materials down to the monolayer limit [Ji et al., Nature (London) 570, 87 (2019)] provided the opportunity to make the two-dimensional (2D) oxide and heterostructure, which could be significantly distinctive from the conventional oxide super...

Physical Review B Structure, Structural phase transitions, Mechanical properties, Defects

Shocked ceramics melt: An atomistic analysis of thermodynamic behavior of boron carbide

Matthew DeVries, Ghatu Subhash, and Amnaya Awasthi

Macroscale experiments for structural response of materials often do not capture deformation features at the atomistic scale. This limitation becomes more pronounced in materials subjected to shock loading, especially in covalently bonded ceramics such as boron carbide, which exhibit a deleterious m...

Physical Review B Structure, Structural phase transitions, Mechanical properties, Defects

Comment on “Thermal vacancies in random alloys in the single-site mean-field approximation”

Dane Morgan and Yongfeng Zhang

This comment concerns the contribution of configurational mixing entropy to the change in the total Gibbs free energy in the process of vacancy formation and the consequent effect on the thermal equilibrium vacancy concentration in multicomponent alloys. A different derivation is shown than that in ...

Physical Review B Structure, Structural phase transitions, Mechanical properties, Defects

Nucleation mechanism for $\mathrm{hcp}→\mathrm{bcc}$ phase transformation in shock-compressed Zr

Hongxiang Zong, Ping He, Xiangdong Ding, and Graeme J. Ackland

We present large-scale atomic simulations of shock-induced phase transition in Zr assisted by the machine learning method. The results indicate that there exists a critical piston velocity of ${U}_{\mathrm{p}}∼0.85\phantom{\rule{0.16em}{0ex}}\mathrm{km}/\mathrm{s}$, above which the product phase has...

Physical Review B Structure, Structural phase transitions, Mechanical properties, Defects

Thickness dependence of hydrogen-induced phase transition in ${\mathrm{MoTe}}_{2}$

Priyanka Manchanda, Pankaj Kumar, and Pratibha Dev

Two-dimensional (2D) transition metal dichalcogenides (TMDs) usually exist in two or more structural phases with different physical properties, and can be repeatedly switched between these phases via different stimuli, making them potentially useful for memory devices. An understanding of the physic...

Physical Review B Structure, Structural phase transitions, Mechanical properties, Defects

Observation of a 1.979-eV spectral line of a germanium-related color center in microdiamonds and nanodiamonds

V. S. Krivobok, E. A. Ekimov, S. G. Lyapin, S. N. Nikolaev, Yu. A. Skakov, A. A. Razgulov, and M. V. Kondrin

Color centers in diamond are considered as a platform for quantum computing and communications, biomedical markers, and nanosensors. Negatively charged split-vacancy centers have outstanding properties due to bright and almost monochromatic luminescence, but they have poor spin coherence and relaxat...

Physical Review B Structure, Structural phase transitions, Mechanical properties, Defects

High-temperature superconductivity in the Ti-H system at high pressures

Jin Zhang, Jeffrey M. McMahon, Artem R. Oganov, Xinfeng Li, Xiao Dong, Huafeng Dong, and Shengnan Wang

Search for stable high-pressure compounds in the Ti-H system reveals the existence of titanium hydrides with new stoichiometries, including $Ibam\text{−}{\mathrm{Ti}}_{2}{\mathrm{H}}_{5}$, $I4/m\text{−}{\mathrm{Ti}}_{5}{\mathrm{H}}_{13}$, $I\overline{4}\text{−}{\mathrm{Ti}}_{5}{\mathrm{H}}_{14}$, $F...

Physical Review B Structure, Structural phase transitions, Mechanical properties, Defects

Prediction of $\mathrm{F}{\mathrm{e}}_{2}\mathrm{P}$-type $\mathrm{TiT}{\mathrm{e}}_{2}$ under pressure

Kai Hu, Jichun Lian, Li Zhu, Qinjun Chen, and Sheng-Yi Xie

$\mathrm{F}{\mathrm{e}}_{2}\mathrm{P}$-type dioxides are significant both for geoscience and condensed-matter physics. For example, $\mathrm{F}{\mathrm{e}}_{2}\mathrm{P}$-type $\mathrm{Si}{\mathrm{O}}_{2}$ has been proposed to be one of the dominant components in the mantles of super-Earths and $\ma...

Physical Review B Structure, Structural phase transitions, Mechanical properties, Defects

Temperature-induced structural change through the glass transition of silicate glass by neutron diffraction

Ying Shi, Ozgur Gulbiten, Jörg Neuefeind, Dong Ma, Albert P. Song, Bryan Wheaton, Mathieu Bauchy, and Stephen R. Elliott

Supercooled silicate liquids exhibit several orders of magnitude increase in viscosity at the glass-transition temperature (${T}_{\mathrm{g}}$) towards the glassy state. Such a drastic dynamical slowdown leads to an abrupt change in the slope of temperature-dependent thermodynamic properties because...

Physical Review B Structure, Structural phase transitions, Mechanical properties, Defects

Elastic Hamiltonians for quantum analog applications

Choonlae Cho, Sunkyu Yu, and Namkyoo Park

Elastic waves are complex mixtures of transverse and longitudinal oscillations even in isotropic and homogeneous media, in contrast to the quantum, electromagnetic, or acoustic waves which could share the same formalism of Hamiltonian and application techniques. Here, we reformulate the elastic wave...

Physical Review B Structure, Structural phase transitions, Mechanical properties, Defects

Breakdown of Arrhenius law of temperature-dependent vacancy concentration in fcc lanthanum

Lucian Mathes, Thomas Gigl, Michael Leitner, and Christoph Hugenschmidt

We measured the temperature-dependent equilibrium vacancy concentration using in situ positron annihilation spectroscopy in order to determine the enthalpy ${H}_{\text{f}}$ and entropy ${S}_{\text{f}}$ of vacancy formation in elementary fcc La. The Arrhenius law applied for the data analysis, howeve...

Physical Review B Structure, Structural phase transitions, Mechanical properties, Defects

Iodine interstitials as a cause of nonradiative recombination in hybrid perovskites

Xie Zhang, Mark E. Turiansky, Jimmy-Xuan Shen, and Chris G. Van de Walle

The identification of deep-level defects that act as detrimental nonradiative recombination centers is critical for optimizing the optoelectronic performance of hybrid perovskites. Although extensive studies have been devoted to revealing the nature of deep-level defects in hybrid perovskites, it is...

Physical Review B Structure, Structural phase transitions, Mechanical properties, Defects

Persistent insulating state at megabar pressures in strongly spin-orbit coupled $\mathrm{S}{\mathrm{r}}_{2}\mathrm{Ir}{\mathrm{O}}_{4}$

Chunhua Chen, Yonghui Zhou, Xuliang Chen, Tao Han, Chao An, Ying Zhou, Yifang Yuan, Bowen Zhang, Shuyang Wang, Ranran Zhang, Lili Zhang, Changjin Zhang, Zhaorong Yang, Lance E. DeLong, and Gang Cao

It is commonly anticipated that an insulating state will collapse in favor of an emergent metallic state at high pressures: The average electron density must increase with pressure, while the electronic bandwidth is expected to broaden and fill the insulating energy band gap. Here we report an unusu...

Physical Review B Structure, Structural phase transitions, Mechanical properties, Defects

Role of spin-orbit coupling in the alloying behavior of multilayer ${\mathrm{Bi}}_{1−x}{\mathrm{Sb}}_{x}$ solid solutions revealed by a first-principles cluster expansion

A. Ektarawong, T. Bovornratanaraks, and B. Alling

We employ a first-principles cluster-expansion method in combination with canonical Monte Carlo simulations to study the effect of spin-orbit coupling on the alloying behavior of multilayer ${\mathrm{Bi}}_{1−x}{\mathrm{Sb}}_{x}$. Our simulations reveal that spin-orbit coupling plays an essential rol...

Physical Review B Structure, Structural phase transitions, Mechanical properties, Defects

Quantum and thermal fluctuations of a thin elastic plate

Dennis P. Clougherty and Eliot Heinrich

We consider a Hamiltonian description of the vibrations of a clamped, elastic circular plate. The Hamiltonian of this system features a potential energy with two distinct contributions: one that depends on the local mean curvature of the plate and a second that depends on its Gaussian curvature. We ...

Physical Review B Structure, Structural phase transitions, Mechanical properties, Defects

Symmetry breakings in a metal organic framework with a confined guest

Céline Mariette, Elżbieta Trzop, Jean-Yves Mevellec, Abdou Boucekkine, Aziz Ghoufi, Guillaume Maurin, Eric Collet, M. Carmen Muñoz, José Antonio Real, and Bertrand Toudic

The MOF $[{\text{Fe(tvp)}}_{2}{(\text{NCS})}_{2}]·2\text{BzCHO}$ is demonstrated to undergo a complex sequence of phase transitions and spin-crossover behavior of its constitutive ${\text{Fe}}^{\text{II}}$ ions upon adsorption of benzaldehyde guest molecules. Our study, combining Raman and synchrotr...

Physical Review B Structure, Structural phase transitions, Mechanical properties, Defects

Single-layer Janus black arsenic-phosphorus (b-AsP): Optical dichroism, anisotropic vibrational, thermal, and elastic properties

L. L. Li, C. Bacaksiz, M. Nakhaee, R. Pentcheva, F. M. Peeters, and M. Yagmurcukardes

By using density functional theory (DFT) calculations, we predict a puckered, dynamically stable Janus single-layer black arsenic-phosphorus (b-AsP), which is composed of two different atomic sublayers, arsenic and phosphorus atoms. The calculated phonon spectrum reveals that Janus single-layer b-As...

Physical Review B Structure, Structural phase transitions, Mechanical properties, Defects

Prediction of perovskite-related structures in $A{\mathrm{CuO}}_{3−x}$ ($A$ = Ca, Sr, Ba, Sc, Y, La) using density functional theory and Bayesian optimization

Atsuto Seko and Shintaro Ishiwata

Here, the authors predict the stability of oxygen-deficient perovskite structures in cuprates by density functional theory calculations. They introduce a combination of cluster expansion, Gaussian process, and Bayesian optimization to find stable oxygen-deficient structures. The calculations not only reproduce the reported structures but suggest the presence of unknown oxygen-deficient perovskite structures, some of which are stabilized at high pressures. This work demonstrates the great applicability of the present computational procedure for the elucidation of the structural stability of strongly correlated oxides.

Physical Review B Structure, Structural phase transitions, Mechanical properties, Defects

Atomistic simulations of dynamics of an edge dislocation and its interaction with a void in copper: a comparative study

Wu-Rong Jian, Min Zhang, Shuozhi Xu and Irene J. Beyerlein

Atomistic simulation methods are appropriate tools for investigating the dynamics of dislocations and their interactions with obstacles in metallic materials. In particular, molecular dynamics (MD) simulations have been widely employed on these two topics in the past several decades. However, even for the same type of simulation, the results can vary. While some of the quantitative differences may be due to the choices of interatomic potential and simulation cell size, they could similarly be attributed to choice of model settings, which have also differed substantially to date. In this paper, we carry out systematic MD simulations to study the effects of a few key model settings on the dynamics of an edge dislocation and its interaction with a void in copper. For a fixed interatomic potential, three modeling parameters, including applied loading mode, boundary conditions, and thermostat, are considered and their influences on the stress–strain response, the dislocation velocity...

Modelling and Simulation in Materials Science and Engineering

Improved energy minimization of iron–carbon systems: on the influence of positioning interstitial atoms

Nina Gunkelmann and Maximilian Merkert

We compare different optimization schemes for the energy minimization in iron–carbon single crystals, where either choosing an initial distribution of interstitial atoms is followed by a conjugate gradient algorithm, or a simulated annealing (SA) procedure is employed. As an alternative to random or so-called single-atom starting configurations, globally optimal interstitial sites with respect to a long-range potential for the carbon–carbon interaction are computed by exact methods of discrete optimization. A comparison of the mechanical properties of the corresponding systems reveals that the positioning scheme can have a large influence. The elastic properties of the crystals for initially randomly distributed carbon atoms show large fluctuations for different initial C interstitial positions. The solution by SA is superior but still causes significant deviations, while using the optimized configurations leads to an increased stiffness of the Fe–C system.

Modelling and Simulation in Materials Science and Engineering

April 02 2020

Implementing Optogenetic Modulation in Mechanotransduction

Miao Yu, Shimin Le, Samuel Barnett, Zhenhuan Guo, Xueying Zhong, Pakorn Kanchanawong, and Jie Yan

Experiments show that light-induced dimerization can be used to control the connectivity of force-transmission linkages in cells, providing a new way to study how cells react to mechanical stimuli.

Physical Review X

Magnetic-Field-Induced Quantum Phase Transitions in a van der Waals Magnet

Siwen Li, Zhipeng Ye, Xiangpeng Luo, Gaihua Ye, Hyun Ho Kim, Bowen Yang, Shangjie Tian, Chenghe Li, Hechang Lei, Adam W. Tsen, Kai Sun, Rui He, and Liuyan Zhao

Spectroscopic measurements explain why a van der Waals ferromagnet displays different magnetic behavior in its layered and bulk forms.

Physical Review X

Complex Distributions Emerging in Filtering and Compression

G. J. Baxter, R. A. da Costa, S. N. Dorogovtsev, and J. F. F. Mendes

A simple filter for marking patterns in a binary sequence produces an output with similar statistics to cooperative systems such as spin glasses and neural networks, providing a potential tool for understanding the statistics in those systems as well.

Physical Review X

Deep Quantum Geometry of Matrices

Xizhi Han (韩希之) and Sean A. Hartnoll

Neural networks enable an important calculation in a popular approach to unifying quantum theory with general relativity.

Physical Review X

Characterizing Multiphoton Excitation Using Time-Resolved X-ray Scattering

Philip H. Bucksbaum, Matthew R. Ware, Adi Natan, James P. Cryan, and James M. Glownia

Using femtosecond x-ray scattering, experiments reveal the ultrafast and ultrasmall motion of molecular iodine in response to intense laser radiation, showing that femtosecond x rays are a powerful tool for studying laser-matter interactions.

Physical Review X

Observation of Anomalous Non-Ohmic Transport in Current-Driven Nanostructures

Guanxiong Chen, Ryan Freeman, Andrei Zholud, and Sergei Urazhdin

Microstructure response to electrical current cannot be described as Joule heating, which warrants a reexamination of many observations of current-induced heating and suggests a new way to study the electron-phonon interaction.

Physical Review X

Microscopic Origin of Capillary Force Balance at Contact Line

JingCun Fan, Joël De Coninck, HengAn Wu, and FengChao Wang

We investigate the underlying mechanism of capillary force balance at the contact line. In particular, we offer a novel approach to describe and quantify the capillary force on the liquid in coexistence with its vapor phase, which is crucial in wetting and spreading dynamics. Its relation with the i...

Physical Review Letters

Kondo-Induced Giant Isotropic Negative Thermal Expansion

D. G. Mazzone, M. Dzero, AM. M. Abeykoon, H. Yamaoka, H. Ishii, N. Hiraoka, J.-P. Rueff, J. M. Ablett, K. Imura, H. S. Suzuki, J. N. Hancock, and I. Jarrige

Negative thermal expansion is an unusual phenomenon appearing in only a handful of materials, but pursuit and mastery of the phenomenon holds great promise for applications across disciplines and industries. Here we report use of x-ray spectroscopy and diffraction to investigate the $4f$-electronic ...

Physical Review Letters

Ultimate Strength of Metals

Michael Chandross and Nicolas Argibay

The peak strength of a metal occurs when the boundaries between its grains and the grains themselves have the same strength.

Physical Review Letters

Two-Dimensional Antimony Oxide

Stefan Wolff, Roland Gillen, Mhamed Assebban, Gonzalo Abellán, and Janina Maultzsch

Two-dimensional (2D) antimony, so-called antimonene, can form antimonene oxide when exposed to air. We present different types of single- and few-layer antimony oxide structures, based on density functional theory (DFT) calculations. Depending on stoichiometry and bonding type, these novel 2D layers...

Physical Review Letters

Three-Phase Fluid Coexistence in Heterogenous Slits

Martin Láska, Andrew O. Parry, and Alexandr Malijevský

We study the competition between local (bridging) and global condensation of fluid in a chemically heterogeneous capillary slit made from two parallel adjacent walls each patterned with a single stripe. Using a mesoscopic modified Kelvin equation, which determines the shape of the menisci pinned at ...

Physical Review Letters

Intercalated $\mathrm{C}{\mathrm{u}}^{+}$ ion dynamics in the two-dimensional layered compound $\mathrm{C}{\mathrm{u}}_{0.33}\mathrm{TiS}{\mathrm{e}}_{2}$

Shunsuke Kitou, Takumi Hasegawa, Akitoshi Nakano, Naoyuki Katayama, Satoshi Tsutsui, and Hiroshi Sawa

$\mathrm{C}{\mathrm{u}}^{+}$ ion behavior is one of the heavily discussed topics in physical and material fields because of its unclear behavior and high potential in materials application. To provide a breakthrough in this field, comprehensive research that connects the real space and the reciproca...

Physical Review B Structure, Structural phase transitions, Mechanical properties, Defects

Tunable Casimir equilibria with phase change materials: From quantum trapping to its release

Lixin Ge, Xi Shi, Zijun Xu, and Ke Gong

A stable suspension of nanoscale particles due to the Casimir force is of great interest for many applications such as sensing, noncontract nanomachines. However, the suspension properties are difficult to change once the devices are fabricated. Vanadium dioxide (${\mathrm{VO}}_{2}$) is a phase chan...

Physical Review B Structure, Structural phase transitions, Mechanical properties, Defects

Higher-order topological phases in a spring-mass model on a breathing kagome lattice

Hiromasa Wakao, Tsuneya Yoshida, Hiromu Araki, Tomonari Mizoguchi, and Yasuhiro Hatsugai

We propose a realization of higher-order topological phases in a spring-mass model with a breathing kagome structure. To demonstrate the existence of the higher-order topological phases, we characterize the topological properties and show that the corner states appear under the fixed boundary condit...

Physical Review B Structure, Structural phase transitions, Mechanical properties, Defects

Switchable phonon diodes using nonlinear topological Maxwell lattices

Di Zhou, Jihong Ma, Kai Sun, Stefano Gonella, and Xiaoming Mao

Recent progress in topological mechanics has revealed a family of Maxwell lattices that exhibit topologically protected floppy edge modes. These modes lead to a strongly asymmetric elastic wave response. In this paper, we show how topological Maxwell lattices can be used to realize nonreciprocal tra...

Physical Review B Structure, Structural phase transitions, Mechanical properties, Defects

Local-structure evidence for a phase transition in a lead-free single crystal of $(\mathrm{N}{\mathrm{a}}_{1/2}\mathrm{B}{\mathrm{i}}_{1/2})\mathrm{Ti}{\mathrm{O}}_{3}\text{−}0.06\mathrm{BaTi}{\mathrm{O}}_{3}$ by absorption fine-structure spectroscopy with synchrotron x-ray radiation

Xiaobing Li, Shengdong Nie, Feifei Wang, Xiangyong Zhao, Haiwu Zhang, Haosu Luo, Guorong Li, Jae-Hyeon Ko, Zhi Guo, Zheng Jiang, and Renzhong Tai

$(\mathrm{N}{\mathrm{a}}_{1/2}\mathrm{B}{\mathrm{i}}_{1/2})\mathrm{Ti}{\mathrm{O}}_{3}\text{−}x\mathrm{BaTi}{\mathrm{O}}_{3}(\mathrm{NBT}\text{−}x\mathrm{BT})$ single crystal, as one of the most promising candidates to replace lead-based ferroelectrics, is a typical and unique lead-free system with ...

Physical Review B Structure, Structural phase transitions, Mechanical properties, Defects

Anisotropic character of the metal-to-metal transition in $\mathrm{P}{\mathrm{r}}_{4}\mathrm{N}{\mathrm{i}}_{3}{\mathrm{O}}_{10}$

Shangxiong Huangfu, Gawryluk Dariusz Jakub, Xiaofu Zhang, Olivier Blacque, Pascal Puphal, Ekaterina Pomjakushina, Fabian O. von Rohr, and Andreas Schilling

As a member of the Ruddlesden-Popper $L{n}_{\mathrm{n}+1}\mathrm{N}{\mathrm{i}}_{\mathrm{n}}{\mathrm{O}}_{3\mathrm{n}+1}$ series rare-earth-nickelates, $\mathrm{P}{\mathrm{r}}_{4}\mathrm{N}{\mathrm{i}}_{3}{\mathrm{O}}_{10}$ consists of infinite quasi-two-dimensional perovskite-like Ni-O based layers...

Physical Review B Structure, Structural phase transitions, Mechanical properties, Defects

First-principles melting of krypton and xenon based on many-body relativistic coupled-cluster interaction potentials

O. R. Smits, P. Jerabek, E. Pahl, and P. Schwerdtfeger

The solid-to-liquid phase transition for krypton and xenon is studied by means of parallel-tempering Monte Carlo simulations based on an accurate description of the atomic interactions within a many-body ansatz using relativistic coupled-cluster theory. These high-level data were subsequently fitted...

Physical Review B Structure, Structural phase transitions, Mechanical properties, Defects

Charge transport in epitaxial barium titanate films

M. Tyunina and M. Savinov

The electrical conductivity of epitaxial $\mathrm{BaTi}{\mathrm{O}}_{3}$ films was studied by small-signal impedance spectroscopy at temperatures of 10–720 K using Pt-$\mathrm{BaTi}{\mathrm{O}}_{3}−\mathrm{SrRu}{\mathrm{O}}_{3}$ capacitors. The $∼150$-nm-thick $\mathrm{BaTi}{\mathrm{O}}_{3}$ films p...

Physical Review B Structure, Structural phase transitions, Mechanical properties, Defects

Structures of solid hydrogen at 300 K

Graeme J. Ackland and John S. Loveday

We present simulated x-ray diffraction patterns (XRD) from molecular dynamics studies of phase transformations in hydrogen at room temperature. Phase changes can be easily identified in simulation, by directly imaging the atoms and measuring correlation functions. We show that the room-temperature X...

Physical Review B Structure, Structural phase transitions, Mechanical properties, Defects

Neutron diffraction and symmetry analysis of the martensitic transformation in Co-doped ${\mathrm{Ni}}_{2}\mathrm{MnGa}$

Fabio Orlandi, Aslı Çakır, Pascal Manuel, Dmitry D. Khalyavin, Mehmet Acet, and Lara Righi

Martensitic transformations are strain driven displacive transitions governing the mechanical and physical properties in intermetallic materials. This is the case in ${\mathrm{Ni}}_{2}\mathrm{MnGa}$, where the martensite transition is at the heart of the striking magnetic shape memory and magnetocal...

Physical Review B Structure, Structural phase transitions, Mechanical properties, Defects

Nonadiabatic effects and excitonlike states during the insulator-to-metal transition in warm dense hydrogen

Ilya D. Fedorov, Nikita D. Orekhov, and Vladimir V. Stegailov

The transition of molecular hydrogen to atomic ionized state with the increase of temperature and pressure poses still unresolved problems for experimental methods and theory. Here we analyze the dynamics of this transition and show its nonequilibrium nonadiabatic character overlooked in both interp...

Physical Review B Structure, Structural phase transitions, Mechanical properties, Defects

Quantum paraelectricity of ${\mathrm{BaFe}}_{12}{\mathrm{O}}_{19}$

Xuefeng Zhang, Qi-Jun Ye, Hongjun Xiang, and Xin-Zheng Li

Using path-integral Monte Carlo sampling and a lattice Wannier function based effective Hamiltonian obtained from first principles, we show that the quantum fluctuations of the nuclei play a central role in the paraelectric phase of ${\text{BaFe}}_{12}{\text{O}}_{19}$ at low temperatures $(T$'s). Co...

Physical Review B Structure, Structural phase transitions, Mechanical properties, Defects

Copper, gold, and platinum under femtosecond irradiation: Results of first-principles calculations

N. A. Smirnov

The paper investigates the interaction of femtosecond laser pulses with the thin films of copper, gold, and platinum. It considers electron-phonon relaxation processes and melting in the metal system nonequilibrium heated by laser radiation. Instead of the approximated formula by Wang et al. [Phys. ...

Physical Review B Structure, Structural phase transitions, Mechanical properties, Defects

Thermodynamics of the insulator-metal transition in dense liquid deuterium

M. P. Desjarlais, M. D. Knudson, and R. Redmer

Recent dynamic compression experiments [M. D. Knudson et al., Science 348, 1455 (2015); P. M. Celliers et al., Science 361, 677 (2018)] have observed the insulator-metal transition in dense liquid deuterium, but with an approximately 95-GPa difference in the quoted pressures for the transition at ...

Physical Review B Structure, Structural phase transitions, Mechanical properties, Defects

Properties of bulk liquid Pd and Pt and their free liquid surface studied with first principles techniques

Beatriz G del Rio, Luis E González and David J González

We have performed first principles computer simulations in order to study the structural and dynamic properties of bulk liquid Pd and Pt near their melting points. We find good agreement with the available experimental static structure and transport properties, and furthermore we provide more detailed information that is not available from experiments. Additional simulations have also been undertaken so as to study the free liquid surface of both liquid metals. The calculated longitudinal ionic density profile exhibits an oscillatory behavior whose properties have been analyzed. For both metals, the associated intrinsic surface structure factor presents a marked maximum related to surface layering.

Modelling and Simulation in Materials Science and Engineering

Thermodynamic modelling of polycrystalline multicomponent multiphase metal alloys

Antonio Mario Locci, Francesco Torre and Francesco Delogu

The present work explores the thermodynamic stability of multicomponent multiphase polycrystalline metal alloys using a theoretical approach based on the regular solution model. We extend the definition of ‘phase’ to homogeneous bodies of any dimensionality, which allows grain boundaries to take on phase-like, or complexion, properties, with energy and chemical composition different from grain interiors. Accordingly, we examine the possible attainment of structural stability due to grain boundary segregation within the framework of equilibrium thermodynamics, making use of a Gibbs free energy function. We also derive a dimensionless version of the model for greater generality, and to properly compare the factors determining the thermodynamic stability of polycrystalline structures. Model predictions are summarized with the help of suitably defined stability maps and a few case studies concerning binary and ternary alloys are discussed.

Modelling and Simulation in Materials Science and Engineering

Implementation of annihilation and junction reactions in vector density-based continuum dislocation dynamics

Peng Lin and Anter El-Azab

In a continuum dislocation dynamics (CDD) formulation by Xia and El-Azab (2015 Modelling Simul. Mater. Sci. Eng. 23 055009), dislocations are represented by a set of vector density fields, one per crystallographic slip systems. The space-time evolution of these densities is obtained by solving a set of dislocation transport equations coupled with crystal mechanics. Here, we present an approach for incorporating dislocation annihilation and junction reactions into the dislocation transport equations. These reactions consume dislocations and result in nothing as in the annihilation reactions, or produce new dislocations of different types as in the case of junction reactions. Collinear annihilation, glissile junctions, and sessile junctions are particularly emphasized here. A generalized energy-based criterion for junction reactions is established in terms of the dislocation density and Burgers vectors of the reacting species, and the reaction rate terms for junction...

Modelling and Simulation in Materials Science and Engineering

Roadmap on multiscale materials modeling

Erik van der Giessen, Peter A Schultz, Nicolas Bertin, Vasily V Bulatov, Wei Cai, Gábor Csányi, Stephen M Foiles, M G D Geers, Carlos González, Markus Hütter, Woo Kyun Kim, Dennis M Kochmann, Javier LLorca, Ann E Mattsson, Jörg Rottler, Alexander Shluger, Ryan B Sills, Ingo Steinbach, Alejandro Strachan and Ellad B Tadmor

Modeling and simulation is transforming modern materials science, becoming an important tool for the discovery of new materials and material phenomena, for gaining insight into the processes that govern materials behavior, and, increasingly, for quantitative predictions that can be used as part of a design tool in full partnership with experimental synthesis and characterization. Modeling and simulation is the essential bridge from good science to good engineering, spanning from fundamental understanding of materials behavior to deliberate design of new materials technologies leveraging new properties and processes. This Roadmap presents a broad overview of the extensive impact computational modeling has had in materials science in the past few decades, and offers focused perspectives on where the path forward lies as this rapidly expanding field evolves to meet the challenges of the next few decades. The Roadmap offers perspectives on advances within disciplines as diverse as p...

Modelling and Simulation in Materials Science and Engineering

March 16 2020

Tesla-Scale Terahertz Magnetic Impulses

Shawn Sederberg, Fanqi Kong, and Paul B. Corkum

Simulations suggest that a relatively simple laser technique could produce femtosecond magnetic-field pulses, which currently are only available at a few major lab facilities.

Physical Review X

Nucleation of Dislocations in 3.9 nm Nanocrystals at High Pressure

Abhinav Parakh, Sangryun Lee, K. Anika Harkins, Mehrdad T. Kiani, David Doan, Martin Kunz, Andrew Doran, Lindsey A. Hanson, Seunghwa Ryu, and X. Wendy Gu

As circuitry approaches single nanometer length scales, it has become important to predict the stability of single nanometer-sized metals. The behavior of metals at larger scales can be predicted based on the behavior of dislocations, but it is unclear if dislocations can form and be sustained at si...

Physical Review Letters

Measuring Dynamic Structural Changes of Nanoparticles at the Atomic Scale Using Scanning Transmission Electron Microscopy

Annelies De wael, Annick De Backer, Lewys Jones, Aakash Varambhia, Peter D. Nellist, and Sandra Van Aert

We propose a new method to measure atomic scale dynamics of nanoparticles from experimental high-resolution annular dark field scanning transmission electron microscopy images. By using the so-called hidden Markov model, which explicitly models the possibility of structural changes, the number of at...

Physical Review Letters

Role of Thermal Equilibrium Dynamics in Atomic Motion during Nonthermal Laser-Induced Melting

Xiaocui Wang, J. C. Ekström, Å. U. J. Bengtsson, A. Jarnac, A. Jurgilaitis, Van-Thai Pham, D. Kroon, H. Enquist, and J. Larsson

This study shows that initial atomic velocities as given by thermodynamics play an important role in the dynamics of phase transitions. We tracked the atomic motion during nonthermal laser-induced melting of InSb at different initial temperatures. The ultrafast atomic motion following bond breaking ...

Physical Review Letters

March 12 2020

Hard X Rays from Laser-Wakefield Accelerators in Density Tailored Plasmas

Michaela Kozlova, Igor Andriyash, Julien Gautier, Stephane Sebban, Slava Smartsev, Noemie Jourdain, Uddhab Chulagain, Yasmina Azamoum, Amar Tafzi, Jean-Philippe Goddet, Kosta Oubrerie, Cedric Thaury, Antoine Rousse, and Kim Ta Phuoc

The output of a compact x-ray source based on laser-generated plasma can be boosted by tailoring the spatial structure of the plasma.

Physical Review X

Coherence of a Driven Electron Spin Qubit Actively Decoupled from Quasistatic Noise

Takashi Nakajima, Akito Noiri, Kento Kawasaki, Jun Yoneda, Peter Stano, Shinichi Amaha, Tomohiro Otsuka, Kenta Takeda, Matthieu R. Delbecq, Giles Allison, Arne Ludwig, Andreas D. Wieck, Daniel Loss, and Seigo Tarucha

A feedback control technique suppresses low-frequency noise in an electron-spin qubit, boosting coherence time and control fidelity.

Physical Review X

Mode-Locked Topological Insulator Laser Utilizing Synthetic Dimensions

Zhaoju Yang, Eran Lustig, Gal Harari, Yonatan Plotnik, Yaakov Lumer, Miguel A. Bandres, and Mordechai Segev

The unique properties of topological physics allow for the design of an array of synchronized, mutually locked semiconductor laser resonators, which could be used as a source of high-power mode-locked laser pulses.

Physical Review X

Quantum Computing with Rotation-Symmetric Bosonic Codes

Arne L. Grimsmo, Joshua Combes, and Ben Q. Baragiola

A unifying framework for quantum error-correcting codes based on collections of bosons allows for the discovery of new codes that provide robust error correction in line with fundamental theoretical limits.

Physical Review X

Marvels and Pitfalls of the Langevin Algorithm in Noisy High-Dimensional Inference

Stefano Sarao Mannelli, Giulio Biroli, Chiara Cammarota, Florent Krzakala, Pierfrancesco Urbani, and Lenka Zdeborová

A tool for benchmarking one of the algorithms most commonly used in machine-learning provides insight into its performance and could lead to a better theoretical understanding of how similar algorithms work.

Physical Review X

Torque and Angular-Momentum Transfer in Merging Rotating Bose-Einstein Condensates

Toshiaki Kanai, Wei Guo, Makoto Tsubota, and Dafei Jin

When rotating classical fluid drops merge together, angular momentum can be advected from one to another due to the viscous shear flow at the drop interface. It remains elusive what the corresponding mechanism is in inviscid quantum fluids such as Bose-Einstein condensates (BECs). Here we report our...

Physical Review Letters

Symmetry-Protected Topological Triangular Weyl Complex

R. Wang, B. W. Xia, Z. J. Chen, B. B. Zheng, Y. J. Zhao, and H. Xu

Weyl points are often believed to appear in pairs with opposite chirality. In this work, we show by first-principles calculations and symmetry analysis that single Weyl phonons with linear dispersion and double Weyl phonons with quadratic dispersion are simultaneously present between two specific ph...

Physical Review Letters

Nonempirical Free Volume Viscosity Model for Alkane Lubricants under Severe Pressures

Kerstin Falk, Daniele Savio, and Michael Moseler

Viscosities $η$ and diffusion coefficients ${D}_{s}$ of linear and branched alkanes at pressure $0<P<0.7\text{ }\text{ }\mathrm{GPa}$ and temperature $T=500–600\text{ }\text{ }\mathrm{K}$ are calculated from molecular dynamics simulations. Combining Stokes-Einstein, free volume, and random wal...

Physical Review Letters

Meron Spin Textures in Momentum Space

Cheng Guo, Meng Xiao, Yu Guo, Luqi Yuan, and Shanhui Fan

We show that a momentum-space meron spin texture for electromagnetic fields in free space can be generated by controlling the interaction of light with a photonic crystal slab having a nonzero Berry curvature. These spin textures in momentum space have not been previously noted either in electronic ...

Physical Review Letters

Morphological Superfluid in a Nonmagnetic Spin-2 Bose-Einstein Condensate

Emi Yukawa and Masahito Ueda

The two known mechanisms for superflow are the gradient of the U(1) phase and the spin-orbit-gauge symmetry. We find the third mechanism, namely a spatial variation of the order-parameter morphology protected by a hidden su(2) symmetry in a nonmagnetic spin-2 Bose-Einstein condensate. Possible exper...

Physical Review Letters

Phonon Thermal Hall Effect in Strontium Titanate

Xiaokang Li, Benoît Fauqué, Zengwei Zhu, and Kamran Behnia

It has been known for more than a decade that phonons can produce an off-diagonal thermal conductivity in the presence of a magnetic field. Recent studies of thermal Hall conductivity, ${κ}_{xy}$, in a variety of contexts, however, have assumed a negligibly small phonon contribution. We present a st...

Physical Review Letters

Interplay of Chemistry and Faceting at Grain Boundaries in a Model Al Alloy

Huan Zhao, Liam Huber, Wenjun Lu, Nicolas J. Peter, Dayong An, Frédéric De Geuser, Gerhard Dehm, Dirk Ponge, Jörg Neugebauer, Baptiste Gault, and Dierk Raabe

The boundary between two crystal grains can decompose into arrays of facets with distinct crystallographic character. Faceting occurs to minimize the system’s free energy, i.e., when the total interfacial energy of all facets is below that of the topologically shortest interface plane. In a model Al...

Physical Review Letters

Spatial Heterogeneities in Structural Temperature Cause Kovacs’ Expansion Gap Paradox in Aging of Glasses

Matteo Lulli, Chun-Shing Lee, Hai-Yao Deng, Cho-Tung Yip, and Chi-Hang Lam

Volume and enthalpy relaxation of glasses after a sudden temperature change has been extensively studied since Kovacs’ seminal work. One observes an asymmetric approach to equilibrium upon cooling versus heating and, more counterintuitively, the expansion gap paradox, i.e., a dependence on the initi...

Physical Review Letters

Secondary-Phase-Assisted Grain Boundary Migration in ${\mathrm{CuInSe}}_{2}$

Chen Li, Ekin Simsek Sanli, Daniel Barragan-Yani, Helena Stange, Marc-Daniel Heinemann, Dieter Greiner, Wilfried Sigle, Roland Mainz, Karsten Albe, Daniel Abou-Ras, and Peter A. van Aken

Significant structural evolution occurs during the deposition of ${\mathrm{CuInSe}}_{2}$ solar materials when the Cu content increases. We use in situ heating in a scanning transmission electron microscope to directly observe how grain boundaries migrate during heating, causing nondefected grains to...

Physical Review Letters

Critical Slowing Down at the Abrupt Mott Transition: When the First-Order Phase Transition Becomes Zeroth Order and Looks Like Second Order

Satyaki Kundu, Tapas Bar, Rajesh Kumble Nayak, and Bhavtosh Bansal

We report that the thermally induced Mott transition in vanadium sesquioxide shows critical slowing down and enhanced variance (“critical opalescence”) of the order parameter fluctuations measured through low-frequency resistance-noise spectroscopy. Coupled with the observed increase of the phase-or...

Physical Review Letters

Frustration and Atomic Ordering in a Monolayer Semiconductor Alloy

Amin Azizi, Mehmet Dogan, Jeffrey D. Cain, Rahmatollah Eskandari, Xuanze Yu, Emily C. Glazer, Marvin L. Cohen, and Alex Zettl

Frustrated interactions can lead to short-range ordering arising from incompatible interactions of fundamental physical quantities with the underlying lattice. The simplest example is the triangular lattice of spins with antiferromagnetic interactions, where the nearest-neighbor spin-spin interactio...

Physical Review Letters

Intrinsic fracture behavior of Mg–Y alloys

Eleanor Mak and W A Curtin

Pure magnesium (Mg) is an attractive metal for structural applications due to its low density, but also has low ductility and low fracture toughness. Dilute alloying of Mg with rare earth elements in small amounts improves the ductility, but the effects of alloying on fracture are not well-established. Here, the intrinsic fracture of a model Mg-3at%Y solid solution alloy is studied using a combination of anisotropic linear elastic fracture mechanics and atomistic simulations applied to a comprehensive set of crack configurations under mode I loading. The competition between brittle cleavage and ductile dislocation emission at the crack tip in Mg is improved slightly by alloying, because local fluctuations of the random solutes enable dislocation emission rather than cleavage fracture for a number of configurations where the differences in critical load for cleavage and emission are small. However, basal-plane cleavage remains strongly preferred, as in pure Mg. The alloys do show...

Modelling and Simulation in Materials Science and Engineering

Efficient numerical method to handle boundary conditions in 2D elastic media

Dénes Berta, István Groma and Péter Dusán Ispánovity

A numerical method is developed to efficiently calculate the stress (and displacement) field in finite 2D rectangular media. The solution is expanded on a function basis with elements that satisfy the Navier–Cauchy equation. The obtained solution approximates the boundary conditions with their finite Fourier series. The method is capable to handle Dirichlet, Neumann and mixed boundary value problems as well and it was found to converge exponentially fast to the analytical solution with respect to the size of the basis. Possible application in discrete dislocation dynamics simulations is discussed and compared to the widely used finite element methods: it was found that the new method is superior in terms of computational complexity.

Modelling and Simulation in Materials Science and Engineering

An efficient implicit time integration method for discrete dislocation dynamics

Gábor Péterffy and Péter Dusán Ispánovity

Plastic deformation of most crystalline materials is due to the motion of lattice dislocations. Therefore, the simulation of the interaction and dynamics of these defects has become state-of-the-art method to study work hardening, size effects, creep and many other mechanical properties of metallic specimens. Lot of efforts have been made to make the simulations realistic by including specific dislocation mechanisms and the effect of free surfaces. However, less attention has been devoted to the numerical scheme that is used to solve the equations of motion. In this paper we propose a scheme that speeds up simulations by several orders of magnitude. The scheme is implicit because this type is the most efficient one for solving stiff equations that arise due to the long-range nature of dislocation interactions. The numerical results show that the method is not only faster than other approaches at the same numerical precision, but it can also be efficiently applied even without di...

Modelling and Simulation in Materials Science and Engineering

March 05 2020

July 20 2020

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Physical Review B Structure, Structural phase transitions, Mechanical properties, Defects

Modelling and Simulation in Materials Science and Engineering