JPS Hot Topics

In 2016, David J. Thouless, F. Duncan M. Haldane, and J. Michael Kosterlitz received the Nobel Prize in Physics for their theoretical discovery of topological phase transitions and topological phases of matter. Their work established the foundation for a new class of matter: topological materials, which exhibit unique properties, stemming from the topological non-triviality of […]

he existence of an overwhelming amount of matter than antimatter in the universe is a fundamental question in physics. The violation of CP symmetry, the combination of charge-conjugation and parity symmetries, called CP violation, is one of the necessary conditions to explain this asymmetry. Fifty years ago, Makoto Kobayashi and Toshihide Maskawa presented a groundbreaking […]

Spin current, or the flow of spin angular momentum, is a central concept in spintronics. With rapid progress in this field, only one side of angular momentum, or spin, has received a lot of attention. The other side, or orbital angular momentum, has long been overlooked, owing to the conventional belief that it is quenched […]

Electrons moving in a magnetic field experience the Lorentz force, causing them to move in circular paths. This creates a magnetic moment that opposes the field, representing the classical orbital magnetic susceptibility for free electrons. In solids, however, electrons are subject to the Coulomb force from periodically aligned atoms. As a result, they adopt Bloch […]

The proton distribution is well-studied via the nuclear charge density distribution derived from electron scattering experiments. Electron scattering is popularly used to estimate nuclear charge distributions, as the electromagnetic interactions are well understood theoretically. Since electron scattering primarily relies on electric charge, it is minimally sensitive to neutrons, which are electrically neutral, making it difficult […]

Multiferroics, materials that exhibit both ferroelectric and magnetic order, have emerged as key platforms for studying strong magnetoelectric interactions, where magnetic and electric properties influence each other. In type-II multiferroics, spontaneous electric polarization arises directly from specific magnetic spin arrangements. When exposed to external oscillating electric and magnetic fields, this spin-driven ferroelectricity generates unique terahertz-range […]

Quantum annealing (QA) is a computational optimization technique that has gained significant attention for solving extremely difficult combinatorial optimization problems. In QA, the optimization problem is encoded into a Hamiltonian and initialized in a superposition of all possible states using a strong transverse field. This field is then adiabatically reduced, guiding the system to its […]

Machine learning techniques have grown rapidly in recent years, and have become indispensable in many fields, including physics. For example, neural networks effectively represent wave functions in many-body quantum systems, where they have been applied to detect phase transitions. Moreover, Monte Carlo sampling and molecular dynamics simulations can be made significantly faster using machine learning. […]

Transition metal-pnictide systems have been extensively studied for decades owing to their unique magnetic properties. Among these, chromium arsenide (CrAs) and manganese phosphide (MnP) are the first chromium and manganese based superconductors, exhibiting unconventional superconductivity under high pressure. CrAs starts superconducting at around 1.2 gigapascals (GPa), while MnP requires pressure as high as 8 GPa. […]

Transport phenomena, especially electron transport, are fundamental processes that are widely studied due to their practical applications in daily life. The Hall effect, for instance, is commonly applied in electronic devices to detect magnetic fields. The topological Hall effect is another such phenomenon, that occurs when electrons are coupled to a non-coplanar magnetic texture with […]