FieldsElectronic structure and electrical properties of surfaces and nanostructures

How Many Excitons Can Combine?

Quantum diffusion Monte Carlo simulation demonstrated the formation of polyexcitons in two-dimensional multi-valley semiconductor systems, where all exciton pairs were energetically bound by equal-strength “chemical bonds.”

Dielectric, optical, and other properties in condensed matter

Electronic structure and electrical properties of surfaces and nanostructures

Topological Properties of the Periodic Toda Lattice: Analogy with the Thouless Pump

We find that the periodic Toda lattice belongs to the same topological class as the Thouless pump.

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

Electronic structure and electrical properties of surfaces and nanostructures

Double Superconductivity in Nodal Line Material NaAlSi; Coexistence of Bulk and 2D Superconductivities

Unique diamagnetic torque signals are found in the nodal line material NaAlSi, which suggests the presence of double superconductivity; i.e., bulk superconductivity and 2D superconductivity on the crystal surface.

Superconductivity

Electronic structure and electrical properties of surfaces and nanostructures

Geometry-Based Nonlinear and Nonequilibrium Phenomena in Solids

Researchers from The University of Tokyo have recently reviewed geometric aspects of nonlinear and nonequilibrium optical phenomena for advanced materials applications in novel solar panels, photodetectors, diodes, and quantum computing.

Electronic structure and electrical properties of surfaces and nanostructures

Dielectric, optical, and other properties in condensed matter

Electronic transport in condensed matter

Electron-Hole Asymmetry Observed in Photoinduced Phase Transition of Excitonic Insulators

During a photoinduced phase transition from an excitonic insulator to a semimetal, photoinduced energy shift of its hole band is delayed than that of its electron band indicating electron-hole asymmetry.

Dielectric, optical, and other properties in condensed matter

Electronic structure and electrical properties of surfaces and nanostructures

Quantum Hall Effect in Bulk (Multilayered) Organic Crystal

The multilayer quantum Hall effect is discovered in an organic massless Dirac electron system, α-(BETS)₂I₃ under pressure at low temperatures and a magnetic field of approximately 1 T.

Electronic structure and electrical properties of surfaces and nanostructures

Electronic transport 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

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

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

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

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

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

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

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

Analyzing Photoinduced Phase Transitions in an Organic Salt Using Floquet Theory

Rich nonequilibrium phase diagrams, including photoinduced topological insulator phases, were theoretically predicted for an organic salt α-(BEDT-TTF)₂I₃ when irradiated by elliptically polarized light.

Electronic structure and electrical properties of surfaces and nanostructures

Dielectric, optical, and other properties in condensed matter

Electronic Structure Transformation in a Magnetized Topological Semimetal

We theoretically show that the nodal structures in topological semimetals, including Weyl points and nodal lines, can be switched by magnetic orders, accompanied by localized states at magnetic domain walls.

Electronic structure and electrical properties of surfaces and nanostructures

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

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

Magnetic Responses of Majorana Kramers Pairs on Time-Reversal Invariant Topological Superconductors

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