JournalJPSJ

NEW
A Solvent Viscositydependent Thermoelectric Conversion Efficiency
2021426
We found a beautiful empirical rule (α ∝ η^{0.4}) between the electrochemical Seebeck coefficient α for Fe^{2+}/Fe^{3+} redox pair and viscosity coefficient η of the organic solvent.
Structure and mechanical and thermal properties in condensed matter

NEW
Nanospaceconfined Helium Shows Fourdimensional Quantum Phase Transition (QPT)
2021419
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

NEW
BKT Phase Transitions in Magnetic Systems: Formations of Narrow Stripes and Vortex–Antivortex Pairs in a Quasi2D Ferromagnet K_{2}CuF_{4}
2021414
Cryogenic Lorentz transmission electron microscopy directly shows that vortex and antivortex pairs emerge in a quasitwodimensional ferromagnet K_{2}CuF_{4}. 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
Crossdisciplinary physics and related areas of science and technology

Singlecrystal NaAlSi Shows Unconventional Superconductivity
2021329
Interesting normal and superconducting states of NaAlSi, a topological nodal line semimetal, were revealed by the measurements using the single crystals grown by the selfflux method.
Superconductivity

Phase Transition and Its Universality Class for a Quantum Spin Chain
2021329
We numerically diagonalize the DimerTrimer (DT) model Hamiltonian around the SU(3) symmetric point. As a result, we discover the phase transition at this point which belongs to the BerezinskiiKosterlitzThouless (BKT)like universality class.
Statistical physics and thermodynamics
Magnetic properties in condensed matter

Splitting Walls: Interplay of Different Orders in Multiferroic Materials
2021329
We theoretically showed an intrinsic splitting instability of composite domain walls in multiferroic materials under field drive. This instability is a direct result of the coexistence of multiple orders in the system.
Magnetic properties in condensed matter
Statistical physics and thermodynamics

PICKUP
Random Numbers Can Help Solve Difficult Problems in Manybody Physics
2021329
Theorists review a random state vectorbased description of quantum manybody systems which helps greatly reduce the computational burden involved in their numerical simulations, opening doors to applications in quantum computing.
Mathematical methods, classical and quantum physics, relativity, gravitation, numerical simulation, computational modeling
Electronic transport in condensed matter
Magnetic properties in condensed matter

PICKUP
Hybrid Quantum–Classical Algorithms: At the Verge of Useful Quantum Computing
2021322
Scientists discuss the recent progress in algorithms that have enabled hybrid quantum–classical computers, which has brought the quest to realize useful quantum computing much closer to its finish line.
Mathematical methods, classical and quantum physics, relativity, gravitation, numerical simulation, computational modeling
Crossdisciplinary physics and related areas of science and technology

Quantum Phase Transition in Spin Dimer Systems
2021322
A magnetic moment fluctuates in both longitudinal and transverse directions. The total moment sum rule is a conservation law that can help us resolve data of neutron scattering into the two components.
Magnetic properties in condensed matter

No Mass Gap Phase Transition in Novel Massless Dirac Fermion Material
2021322
Using an organic massless Dirac fermion system, we found that massless Dirac fermions undergo a quantum phase transition without creating any mass gap even in the strong coupling regime.
Electron states in condensed matter
Electronic transport in condensed matter

Of Spins and Atoms: Combining Rotations to Obtain Directed Motion
2021322
The coupling between surface acoustic waves and spin waves is shown to depend strongly on the angle between the acoustic wavevector and magnetization. For a particular angle, it completely vanishes in one direction, which enables a unidirectional generation of surface acoustic waves by a ferromagnetic resonance.
Magnetic properties in condensed matter
Electromagnetism, optics, acoustics, heat transfer, and classical and fluid mechanics

Reducing the Number of Tests Using Bayesian Inference to Identify Infected Patients in Group Testing
2021322
Group testing is a method of identifying infected patients by performing tests on a pool of specimens. Bayesian inference and a corresponding belief propagation (BP) algorithm are introduced to identify the infected patients in group testing.
Statistical physics and thermodynamics
Crossdisciplinary physics and related areas of science and technology

Exploring the Pseudogap in Cuprate Superconductors
2021322
Electronic nematic correlation, in which electronic degree of freedom breaks the crystal symmetry, was found to have a potential link to the origin of hightemperature superconductivity in cooper oxide materials.
Superconductivity

Under Pressure: Getting the Electronic State of Europium Ions to Changes
2021315
Scientists show how pressure and quantum phenomena interplay to alter Europium’s electronic states in a unique manner, opening doors to novel applications in spintronics and technology.
Magnetic properties in condensed matter

On and Off: The Physics Behind Photoswitchable Magnetic Octacyanometalates
2021315
We make a major breakthrough in understanding the photoswitchable magnetism in squareantiprismatic octacyanometalates. We reveal that the ``bidirectional” magnetism is accompanied by ``monodirectional electronics” to find a possibility of fabricating multifunctional magnetic devices.
Dielectric, optical, and other properties in condensed matter
Magnetic properties in condensed matter

How is Brownian Motion Affected by a Fluctuating Random Surface?
2021315
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

Taking a Better Look at Data to Predict Exceptional Materials
2021315
Instead of regression, the evaluation values to measure the degree of separation of the distributions of the target variable were studied and applied to the magneto crystallineanisotropy of Co/Fe films.
Crossdisciplinary physics and related areas of science and technology
Magnetic properties in condensed matter

Using Analogy to Understand Localization in Quantum Annealing
2021315
Localization may cause the inefficiency of quantum annealing. The constrained quantum annealing of graph coloring provides a new viewpoint to analyze localization phenomena in quantum annealing.
Statistical physics and thermodynamics

Solving Quantum Equations with Gauge Fields: How Explicit Integrators Based on a Bipartite Lattice and Affine Transformations Can Help
2021315
We proposed an explicit numerical integrator consisting of affine transformation pairs resulting from the checkerboard lattice for spatial discretization. It can efficiently solve time evolution equations that describe dynamical quantum phenomena under gauge fields, e.g., generation, motion, interaction of quantum vortices in superconductors or superfluids.
Mathematical methods, classical and quantum physics, relativity, gravitation, numerical simulation, computational modeling
Superconductivity

Extending Machine Learning to Fermion–Boson Coupled Systems and ExcitedState Calculations
2021315
We have demonstrated the power of machine learning in representing quantum manybody states accurately. We have extended the applicability of neuralnetwork wave functions and shown their usefulness in fermionbosoncoupled systems and excitedstate calculations.
Magnetic properties in condensed matter
Structure and mechanical and thermal properties in condensed matter

PICKUP
Review of CuttingEdge Research on Iron Selenide Superconductors
202133
Scientists review the incredible progress in our understanding of the superconducting properties of iron selenide and provide their own insights, taking us one step closer to revolutionizing energy and electronics
Superconductivity
Crossdisciplinary physics and related areas of science and technology

Hydrogen Science: Exploring the Properties of our Universe’s Smallest Building Block
202133
Reviews on the most recent advances in hydrogen science, including cuttingedge fundamental studies in condensed matter physics with hydrogencontaining materials.

Toward a Hydrogen Society: Harnessing the Power of the Smallest Element
202133
Comprehensive curated reviews by researchers on the latest research in hydrogenrelated applications, including proton conductors, superconductivity, electrochemistry with hydrides, and more.

Novel Material Shows Unconventional Superconductivity with Magnetic Order Under Pressure
202133
Multiple superconductivity wad found in the novel spintriplet superconductor UTe_{2}, which is called “Silicon of Quantum Computers”. A complicated spintriplet state is realized as a consequence of spin degree of freedom. This result will lead to a new state of topological superconductivity.
Superconductivity
Magnetic properties in condensed matter

Multiple Superconducting Phases in UTe_{2}: A Complex Analogy to Superfluid Phases of ^{3}He
202133
In quantum liquids, large differences are observed owing to differences in quantum statistics. The physical properties of liquid ^{3}He (Fermion) and ^{4}He (Boson) are considerably different at low temperatures. After the discovery of superconductivity in electron (i.e., Fermion) systems, a similar pairing ordered state was expected for ^{3}He. Remarkably, the observed ordered state of ^{3}He was more surprising than expected, multiple superfluid phases in the T–P phase diagram. The origin of the multiple phases was attributed to ferromagnetic interactions in the pwave symmetry state.
Superconductivity
Magnetic properties in condensed matter

Magnetic Responses of Majorana Kramers Pairs on TimeReversal Invariant Topological Superconductors
202133
We reveal magnetic degrees of freedom of Majorana fermions and find a new type of response that are distinct from those of conventional electrons.
Superconductivity
Electronic structure and electrical properties of surfaces and nanostructures

What Dictates Nonlinear Behavior in Strongly Correlated Insulators?
202133
The nonlinear conduction (the deviation from Ohm's law) has been discovered universally in various correlated materials. This may be explained by the percolation conduction in disordered materials.
Electronic transport in condensed matter
Statistical physics and thermodynamics