FieldsStructure and mechanical and thermal properties in condensed matter

Evaluation of the Exchange Stiffness Constants of Itinerant Magnets from the First-Principles Calculations

Using first-principles calculations, we evaluated the exchange stiffness constants of ferromagnetic metals at finite temperatures. The constants can be used as parameters in the Landau–Lifshitz–Gilbert equation.

Electron states in condensed matter

Structure and mechanical and thermal properties in condensed matter

Which is Moving?—Pinning Down the Origin of Fluctuations in Muon Spin Relaxation—

The study demonstrated that we can distinguish between the diffusion motion of the muon itself and the motion of the surrounding ions in muon spin relaxation.

Structure and mechanical and thermal properties in condensed matter

Cross-disciplinary physics and related areas of science and technology

Variety of Mechanically Induced Spin Currents in Rashba Systems

Various types of spin currents, including unconventional types, are generated in Rashba spin-orbit coupled systems by dynamic lattice distortions associated with, for example, surface acoustic waves.

Electronic transport in condensed matter

Magnetic properties in condensed matter

Structure and mechanical and thermal properties in condensed matter

Relation between Mean-Field Theory and Atomic Structures in Chalcogenide Glasses

The authors conducted various of X-ray and neutron scattering experiments on typical chalcogenide glasses and clarified the relationship between the atomic structure and simple rigidity percolation theory.

Structure and mechanical and thermal properties in condensed matter

Possible Origin of High Thermoelectric Power Factor in Ultrathin FeSe: A Two-band Model

The high thermoelectric power factor observed in ultrathin FeSe can be theoretically explained by a two-band model with chemical potential between upper and lower band bottoms.

Electronic structure and electrical properties of surfaces and nanostructures

Structure and mechanical and thermal properties in condensed matter

Cross-disciplinary physics and related areas of science and technology

Exploring Recent Advances in the Physics of Biofluid Locomotion

This Special Topics Edition of the JPSJ describes the latest advances in the field of biofluid locomotion, shedding light on the underlying physics behind the movement of organisms that swim and fly.

Measurement, instrumentation, and techniques

Cross-disciplinary physics and related areas of science and technology

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

Statistical physics and thermodynamics

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

Structure and mechanical and thermal properties in condensed matter

Strange Elastic Anomalies with Ultraslow Dynamics around Magnetic Critical Endpoint

Near the magnetic critical endpoint of UCoAl, peculiar elastic anomalies exhibiting exotic ultraslow dynamics arising from electric quadrupoles are indicated. Combining this with diverse fluctuations, intriguing phenomena and exotic ground states are expected.

Structure and mechanical and thermal properties in condensed matter

Magnetic properties in condensed matter

Towards a New Phase in Materials Science with Hyperordered Structures

A Special Topics edition of the Journal of the Physical Society of Japan features articles discussing recent advancements in hyperordered structures in materials, their applications, and the techniques for observing them.

Structure and mechanical and thermal properties in condensed matter

Cross-disciplinary physics and related areas of science and technology

Dielectric, optical, and other properties in condensed matter

Electron states in condensed matter

Atomic and molecular physics

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

What Determines Non-Newtonian Flow Behavior in Glass-Forming Liquids?

Even minute structural changes can lead to significant reductions in the flow resistances of glass-forming liquids. Here, possible scenarios and predictions for two different classes of glass-forming liquids are provided.

Cross-disciplinary physics and related areas of science and technology

Structure and mechanical and thermal properties in condensed matter

Clockwise or Anticlockwise, That is the Question: Phonons with Angular Momentum in Chiral Crystals

Chiral crystals have lattice structures with no mirror or inversion symmetries.
A few basic questions about their unique phonon excitations with intrinsic angular momentum are answered.

Structure and mechanical and thermal properties in condensed matter

Angle-Resolved Photoelectron Spectroscopy Microscopy: A Tool to Accelerate Nanomaterials Research

Researchers have published a practical guide on new uses of photoelectron microscopy combined with valence band dispersion analysis. They visualized several-micrometers-wide graphite facets and precisely characterized the band structure.

Electronic structure and electrical properties of surfaces and nanostructures

Structure and mechanical and thermal properties in condensed matter

Cross-disciplinary physics and related areas of science and technology

Powered by Machine Learning: Obtaining Spectral Conductivity and Chemical Potential of Thermoelectric Materials from Experimental Data

We propose a machine-learning method to obtain the fundamental physical quantity, namely, the spectral conductivity, from experimental data of thermoelectric coefficients. Our study introduces a new data-driven approach that reveals the underlying low-energy electronic states of high-performance thermoelectric materials.

Structure and mechanical and thermal properties in condensed matter

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

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

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

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

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

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

Exploring the Basic Principles and Functionalities of Spintronic Thermal Management

Scientists propose a new spin caloritronics concept called “spintronic thermal management” and provide a comprehensive overview of basic principles, physical behaviors, and heat control functionalities associated with the concept.

Magnetic properties in condensed matter

Structure and mechanical and thermal properties in condensed matter

The Mysteries of Charge Order and Charge Fluctuations in Cuprate Superconductors

This Special Topics issue condenses the latest research on the enigmatic characteristics of high-temperature superconductivity in cuprates through the observation and elucidation of charge order, charge fluctuations, and other phenomena.

Superconductivity

Dielectric, optical, and other properties in condensed matter

Structure and mechanical and thermal properties in condensed matter

Magnetic properties in condensed matter

Exploring the Thermoelectric Properties of Nitrogen-doped Carbon Nanotubes

A semiconducting carbon nanotube doped with an optimal concentration of nitrogen delivered a thermoelectric power substantially higher than that delivered by commercial Bi₂Te₃ alloys.

Electronic transport in condensed matter

Structure and mechanical and thermal properties in condensed matter

Cross-disciplinary physics and related areas of science and technology

Finding Pattern in Randomness: Brownian Motion of Skyrmions

The chiral properties of the Brownian motion of magnetic skyrmions in one- and two-dimensional systems in thermal equilibrium are reported.

Structure and mechanical and thermal properties in condensed matter

Electronic transport in condensed matter

Magnetic properties in condensed matter

Nonlinear Thermoelectric Transport Will Open a New and Exotic Way to Detect Topological Nature of Dirac Electrons in Solids

Recently, it was proposed that a novel nonlinear anomalous Ettingshausen effect enabled a new and exotic approach to observe topological nature of Dirac electrons in solids using thermoelectric properties.

Electronic transport in condensed matter

Electronic structure and electrical properties of surfaces and nanostructures

Structure and mechanical and thermal properties in condensed matter

Exploring the Physics of Ferrimagnets for Future Spintronics Applications

This Special Topics collection of the Journal of the Physical Society of Japan covers recent progress in spintronics research on ferrimagnetic materials.

Structure and mechanical and thermal properties in condensed matter

Electronic transport in condensed matter

Magnetic properties in condensed matter

Cross-disciplinary physics and related areas of science and technology

Uncovering the Superlattice Structure of Calcium Iridium Oxide at Phase Transition

Order parameter of non-magnetic phase transition at 105 K, which is called "hidden order", was revealed in spin-orbit coupled iridate Ca₅Ir₃O₁₂. This discover of order parameter with rotational and directional degrees of freedom in atomic scale will lead to development of energy saving devices with a fast cross-correlated response.

Electron states in condensed matter

Structure and mechanical and thermal properties in condensed matter

Descriptor of Thermogalvanic Cell for Waste-heat Harvesting

The scaling relation between the Seebeck coefficient and solvent viscosity would enable for the design of improved thermogalvanic cells.

Structure and mechanical and thermal properties in condensed matter

How a Potentially Novel Effect Converts AC Current into DC Heat Flow

A novel current-induced thermoelectric phenomenon, the nonlinear anomalous Ettingshausen effect, was discussed. As an example, the weak charge ordering state in an organic conductor α-(BEDT-TTF)₂I₃ was focused on. This effect generates a transverse heat current with rectifying characteristics, namely unidirectionality even under AC fields.

Electronic transport in condensed matter

Electronic structure and electrical properties of surfaces and nanostructures

Structure and mechanical and thermal properties in condensed matter

A Solvent Viscosity-dependent Thermoelectric Conversion Efficiency

We found a beautiful empirical rule (α ∝ η^-0.4) between the electrochemical Seebeck coefficient α for Fe²⁺/Fe³⁺ redox pair and viscosity coefficient η of the organic solvent.

Structure and mechanical and thermal properties in condensed matter

Nanospace-confined Helium Shows Four-dimensional Quantum Phase Transition (QPT)

Helium confined in a nanoporous material shows a four dimensional superfluid transition. This is a unique example of four dimensional critical phenomenon caused by strong quantum fluctuation.

Structure and mechanical and thermal properties in condensed matter

BKT Phase Transitions in Magnetic Systems: Formations of Narrow Stripes and Vortex–Antivortex Pairs in a Quasi-2D Ferromagnet K₂CuF₄

Cryogenic Lorentz transmission electron microscopy directly shows that vortex and antivortex pairs emerge in a quasi-two-dimensional ferromagnet K₂CuF₄. This work may reveal the nature of Berezinskii, Kosterlitz, and Thouless phase transition in a magnetic system.

Magnetic properties in condensed matter

Structure and mechanical and thermal properties in condensed matter

Cross-disciplinary physics and related areas of science and technology

How is Brownian Motion Affected by a Fluctuating Random Surface?

A researcher has developed a new theory to describe the Brownian motion of a small object that is confined in a fluctuating random surface.

Statistical physics and thermodynamics

Structure and mechanical and thermal properties in condensed matter

Extending Machine Learning to Fermion–Boson Coupled Systems and Excited-State Calculations

We have demonstrated the power of machine learning in representing quantum many-body states accurately. We have extended the applicability of neural-network wave functions and shown their usefulness in fermion-boson-coupled systems and excited-state calculations.

Magnetic properties in condensed matter

Structure and mechanical and thermal properties in condensed matter