Year2022

Phonon Simulations and Its Applications

Computation of phonons using first principles has many applications for understanding crystal properties. This review provides an overview of the present capabilities of such simulations using finite displacement supercell approach.

Structure and mechanical and thermal properties in condensed matter

High Magnetic Field as a Tool for Discovery in Condensed Matter Physics

The Journal of the Physical Society of Japan highlights in this special topic recent advances in modern physics that have been realized with the generation of pulsed high magnetic fields.

Magnetic properties in condensed matter

Dielectric, optical, and other properties in condensed matter

Electronic transport in condensed matter

Structure and mechanical and thermal properties in condensed matter

Electron states in condensed matter

Electronic structure and electrical properties of surfaces and nanostructures

Measurement, instrumentation, and techniques

Terahertz Radiation as a Tool for Exploring Material Properties

Researchers from Japan highlight, in a recent review, the range of material properties that can be and have been studied using the phenomenon of femtosecond laser-induced terahertz radiation emission.

Dielectric, optical, and other properties in condensed matter

Insights into the Overlooked Electric Ferro-Axial Ordering

We theoretically demonstrate spin related conductivity under electric ferro-axial ordering. We show an intrinsic generation of a spin current parallel to an applied electric field in metals and insulators.

Understanding the Obscure Antiferromagnetism in α-Mn by Nuclear Magnetic Resonance

Although Mn is an elementary metal, the antiferromagnetic state of α-Mn is still obscure. Our NMR study on high-quality α-Mn provides new insights into the symmetry of its antiferromagnetism.

Magnetic properties in condensed matter

Theoretical Assessment of F-wave Bottom Mesons and Their Properties

We use heavy quark effective theory to study F-wave bottom mesons. Using theory and experimental data, we calculate their masses and analyze their decay widths to estimate the upper bound to the associated couplings.

Theoretical Particle Physics

Towards a Better Understanding of the Short-range Repulsive Nuclear Force

In a new study, researchers provide an experimental estimate of the short-range repulsive nuclear force strength based on a high-statistics measurement of the differential cross-section for Σ⁺p scattering.

Nuclear physics

Observing the de Haas–van Alphen Effect to Unveil the Electronic Structure of UTe₂ Superconductor

The topology of Fermi surfaces with heavy effective masses in strongly correlated topological superconductor UTe₂ was investigated using quantum oscillation measurements and theoretical calculations.

Electron states in condensed matter

Superconductivity

Strange Metal Behavior Potentially Associated to Hidden Electronic Nematicity

Iron-based superconductor, Ba_1-xRb_xFe₂As₂, exhibits “strange metal” behavior—linear dependence of resistivity on temperature. It seems that hidden electronic nematic fluctuations play a greater role than the well-known antiferromagnetic fluctuations.

Superconductivity

Electronic transport in condensed matter

Thermoelectric Response in Strongly Disordered Systems

Based on the Kubo–Luttinger linear response theory, we discovered that the low-T Seebeck coefficient for Mott variable-range hopping in a d-dimensional system varies as S ∝ T^d/(d+1), which is different from the conventional S ∝ T^{(d−1)/(d+1)}. In addition, the experimental data for S of CuCrTiS₄ at low T are in excellent agreement with our prediction S ∝ T^3/4 (d = 3).

Electronic transport in condensed matter

Representations of KBc Algebra for Generating String Field Theory Solutions

We propose a general method for generating solutions in string field theory from a solution constructed using KBc algebra, and reproduce known solutions constructed earlier using different methods.

Theoretical Particle Physics

Birefringence Imaging-Based Investigation of Stress-Induced Phase Transitions in SrTiO₃

The spatial distributions of ferroelectric and structural phase transitions in quantum paraelectric SrTiO₃ under uniaxial stress were microscopically observed using birefringence imaging techniques.

Dielectric, optical, and other properties in condensed matter

Topology-Based Method for Determining the Order Parameter of the Putative Spin-Triplet Superconductor UTe₂

The intrinsic anomalous thermal Hall effect can be an effective probe for the order parameters of non-unitary pairing states of the putative spin-triplet superconductor UTe₂

Superconductivity

Inertial Focusing of Red Blood Cells in Square Tube Flows

Red blood cells flowing through square capillary tubes were observed to migrate towards four points located on the diagonal in the tube cross-section, owing to their deformability and inertia.

Electromagnetism, optics, acoustics, heat transfer, and classical and fluid mechanics

Can a Node-Less Wave Function Have Higher Energy than Node-Full Ones?

“The energy level of an electron state increases as the number of nodes in its wave function increases.” The preceding statement, often found in textbooks, was challenged by our large-scale DFT (density-functional theory) calculations performed for the decavacancy in Si crystal.

Electron states in condensed matter

Structure and mechanical and thermal properties in condensed matter

Optical Tweezer Arrays with Ytterbium Atoms for Studying Quantum Phenomena

A neutral Rydberg atom tweezer array is a promising platform for quantum computation. In this study, featuring its metastable excited state, an array of single ytterbium atoms trapped in micro-optical tweezers was constructed. This overcomes many problems in conventional systems using alkali atoms.

Atomic and molecular physics

Spin-Orbit Coupled Electrons on Kagome Lattice Give Rise to Various Magnetic Orderings

Diverse magnetic orderings are found to be produced by spin-orbit coupled electrons on the kagome lattice. This finding provides a unified guiding principle for the design of magnetic topological materials.

Electronic structure and electrical properties of surfaces and nanostructures

Open String Field Theory Beyond Feynman Diagrams

Theoretical physicists propose an alternative way of performing perturbative calculations in an open string field theory that has no analogy in the standard quantum field theory formalism.

Elementary particles, fields, and strings

Theoretical Particle Physics

A New Route to the Realization of Topological Superconductivity

We theoretically suggest that topological Weyl superconductivity can be realized by applying a supercurrent to noncentrosymmetric line-nodal superconductors with spin–orbit coupling.

Superconductivity

Electronic structure and electrical properties of surfaces and nanostructures

Exploring Superconductivity in the Close Proximity of Polar-Nonpolar Structural Phase Transition

A polar-nonpolar structural phase transition and corresponding increase in superconducting transition temperature T_c are observed in chemically doped PtBi₂. T_c increases as the system approaches the phase boundary.

Superconductivity

New Phases of Matter: Topological Physics in the 21^st Century

Researchers from Japan highlight in an editorial our current understanding of topological phases of matter, focusing on the classification of the newly discovered symmetry protected topological phases.

Theoretical Particle Physics

Fundamental Theory of Condensed Matter Physics, Statistical Mechanics, Fluid Dynamics,

Superconductivity

Giant Vortices of Fish: Mechanisms and Patterns

The origin of giant rotating clusters of fish is revealed by a new agent-based model that incorporates the topological nature of interactions and the escape response characteristic to fish.

Cross-disciplinary physics and related areas of science and technology

Calculating Impedances for a Particle Accelerator

In a new study, scientists provide a more comprehensive picture of dealing with the impedances of a two-dimensional conductive cylindrical beam pipe with walls of finite thickness and space-charge forces simultaneously.

Beam Physics

Origin of Metamagnetic Transition (MMT) in the Spin-Triplet Superconductivity in UTe₂

State-of-the-art magnetostriction measurements in a pulsed-magnetic field reveal the origin of a metamagnetic transition of spin-triplet superconductor UTe₂. We propose that the uranium valence fluctuation plays a crucial role in its metamagnetic and superconducting transitions.

Superconductivity

Magnetic properties in condensed matter

Unraveling the Unique Properties of Icosahedral Quasicrystals

Scientists review the magnetism, non-Fermi liquid behavior, and quantum critical behavior observed in icosahedral quasicrystals (QCs), and compare these properties with that of heavy fermions and approximant crystals.

Magnetic properties in condensed matter

Structure and mechanical and thermal properties in condensed matter

Cross-disciplinary physics and related areas of science and technology

Testing the Viability of Muon Accelerators

Researchers demonstrate the viability of a radio-frequency linear accelerator to accelerate stopped muons to the speed of light.

Experimental Particle Physics

New Chiral Molecular Ferroelectrics

A new chiral ferroelectric material is discovered in a purely organic system, 1,1’-bi-2-naphthol・2 dimethyl sulfoxide (BINOL・2DMSO).

Dielectric, optical, and other properties in condensed matter

Tensor Networks Across Physics

Researchers from Japan provide the first comprehensive review of the historical development of tensor networks from a statistical mechanics viewpoint, with a focus on its theoretical background.

Mathematical methods, classical and quantum physics, relativity, gravitation, numerical simulation, computational modeling

Statistical physics and thermodynamics

Magnetic properties in condensed matter

Towards Radionuclide Cancer Therapy with High Purity ¹⁷⁷Lu from Enriched ¹⁷⁶Yb Samples

A method was developed to estimate the isotopic compositions of enriched ¹⁷⁶Yb sample required for producing radionuclide ¹⁷⁷Lu used for cancer therapy, with high radionuclide purity in accelerators.

Nuclear physics

Cross-disciplinary physics and related areas of science and technology

Simulating Strongly Coupled Quantum Field Theory with Quantum Algorithms

Nonperturbative quantum field theory problems can often be difficult to solve with classical algorithms. Researchers now develop quantum computing algorithms to understand such problems in the Hamiltonian formalism.

Theoretical Particle Physics

Understanding Relaxor Ferroelectrics with Simple Landau Theory

Third-order nonlinear dielectric susceptibility is measured in the paraelectric phase of Pb(Sc_1/2Ta_1/2)O₃. The linear and nonlinear dielectric susceptibility results can be consistently explained based on the Landau-type free-energy density.

Dielectric, optical, and other properties in condensed matter

Structure and mechanical and thermal properties in condensed matter

Cross-disciplinary physics and related areas of science and technology

Getting Around the Sign Problem to Solve an Open Quantum System

Researchers from Japan have found a novel non-equilibrium quantum system that doesn’t have the sign problem. The transport properties of the system are simulated with a Monte Carlo approach.

Elementary particles, fields, and strings

Theoretical Particle Physics

Quantum Anomaly in a Dirac Fermion System with Spacetime Dependent Mass

Scientists investigate quantum anomalies in a system of Dirac fermions with spacetime dependent mass and show that the anomaly formulas can be expressed in terms of superconnections.

Theoretical Particle Physics

Elementary particles, fields, and strings

Spin Transport in a Two-Dimensional Tilted Dirac Electron System

We propose that spin current in an organic conductor, α-(BETS)₂I₃, is an appropriate physical quantity to detect the topological nature of the material whose electrons obey a quasi-two-dimensional Dirac equation.

Electronic transport in condensed matter

Electronic structure and electrical properties of surfaces and nanostructures

Violation of Fluctuation-Dissipation Theorem Results in Robustness of Fluctuation Against Localization

We study equilibrium current fluctuations in systems without time-reversal symmetry, violating the fluctuation-dissipation theorem. Notably, the off-diagonal fluctuation is insensitive to system imperfections in contrast to other fluctuations and conductivity.

Statistical physics and thermodynamics

Electronic transport in condensed matter

Electronic structure and electrical properties of surfaces and nanostructures

Four-Dimensional XY Quantum Phase Transition in Superfluid Helium-4

Liquid helium confined in nanopores exhibits a quantum superfluid transition at absolute zero. Investigations have revealed that the quantum nature also dominates the finite-temperature superfluid transition, obeying a simple mean-field theory.

Structure and mechanical and thermal properties in condensed matter

Topological Aspects of a Nonlinear System: The Dimerized Toda Lattice

A nonlinear topological phase is shown to emerge in the dimerized Toda lattice. It is experimentally detectable by measuring the voltage propagation in electric circuits.

Electronic structure and electrical properties of surfaces and nanostructures

Electronic transport in condensed matter

Unusual Nonlinear Conductivity in Charge-Ordered α-(BEDT-TTF)₂I₃

Unusual nonlinear conduction is detected in organic molecular salt α-(BEDT-TTF)₂I₃. The observed third-order nonlinear conductivity implies a quadrupole instability hidden in this charge-ordered organic salt.

Electronic transport in condensed matter

Economic Irreversibility: The Universal Guiding Principle of Infection Control

It is preferable to avoid lockdowns, as lockdowns at seriously spread phases are very expensive. It would be economically better to utilize less intense countermeasures as early as possible to avoid lockdowns in later phases.

Statistical physics and thermodynamics

Cross-disciplinary physics and related areas of science and technology

High-Precision Observation of Cosmic Gamma-ray Sources with the GRAINE Telescope

A gamma-ray telescope developed jointly by universities in Japan promises an unprecedented imaging resolution that could help distinguish gamma-ray sources observed in our galaxy.

Measurement, instrumentation, and techniques

Calculating Superconformal Index of 𝓝 = 4 Super-Yang-Mills Theory for Finite N

The examination of AdS/CFT correspondence for finite N, where quantum gravitational effects become important, reveals that finite N corrections for the superconformal index can be reproduced as D-3 brane contributions.

Theoretical Particle Physics

Realizing Spin Liquids Experimentally with Kapellasite-type Quantum Kagome Antiferromagnet

This study reports the observation of the spin fluctuation in a quantum kagome antiferromagnet CaCu₃(OH)₆Cl₂·0.6H₂O which persists down to 82 mK using the μSR technique.

Magnetic properties in condensed matter

Phosphorous-Based Zintl Compounds as Viable Semimetals

A black-phosphorus-derived Zintl compound, MoP₄, is obtained by high-pressure synthesis. The material exhibits a non-quadratic large magnetoresistance and semi-metallic Seebeck behavior, as predicted by the first principles calculations yielding massive and non-symmorphic Dirac semimetal states.

Electronic structure and electrical properties of surfaces and nanostructures

Structure and mechanical and thermal properties in condensed matter

Electron states in condensed matter

New Systematic Analysis Method of Identifying Microscopic Essential Couplings

We propose a systematic method of identifying essential model parameters for nonlinear response tensors. The analysis results reveal fundamental couplings in nontrivial responses and promote further development of multiferroic responses.

Electronic transport in condensed matter

Dielectric, optical, and other properties in condensed matter

Cross-disciplinary physics and related areas of science and technology

Shedding Light on Nonreciprocal Directional Dichroism at High Magnetic Fields in a Multiferroic Material

Large optical nonreciprocal directional dichroism, coupled with an antiferromagnetic order parameter, is observed in a high magnetic field via magneto-optical spectroscopy combined with a pulse magnet technique.

Dielectric, optical, and other properties in condensed matter

Magnetic properties in condensed matter

Twist in the Tale: Exploring the Dielectric Screening Effect in Twisted Bilayer Graphene

Although the screening of an external electric field, strongly influences the electronic states of two-dimensional material stack, it is not well understood. Magnetotransport measurements of twisted double bilayer graphene uncovered the screening of atomic layers.

Electronic structure and electrical properties of surfaces and nanostructures

Electronic transport in condensed matter