Article
Physics, Condensed Matter
Shubhajyoti Mohapatra, Avinash Singh
Summary: The study investigates the pseudo-spin rotation symmetry of different Coulomb interaction terms under SU(2) transformation in pseudo-spin space. It was found that the Hund's coupling and pair-hopping interaction terms systematically break the pseudo-spin rotation symmetry, leading to the formation of easy x-y plane anisotropy and magnon gap.
JOURNAL OF PHYSICS-CONDENSED MATTER
(2021)
Article
Physics, Multidisciplinary
Deshui Yu, Frank Vollmer
Summary: This study introduces a new model that takes into account the internal dynamics of active particles, and numerically investigates the PT symmetry of macroscopic- and microscopic-sized laser systems operating in the strong-coupling regime. Distinct phase diagrams are drawn based on the features of intracavity photon numbers and emission spectra. This work extends PT-symmetric optics from weak to strong coupling limits, potentially leading to nonclassical PT-symmetric light sources for integrated photonic networks and ultrasensitive sensors.
COMMUNICATIONS PHYSICS
(2021)
Article
Mathematics, Applied
Zhaopin Chen, Yongyao Li, Yan Liu, Boris A. Malomed
Summary: By using numerical methods, it is found that symmetric two-layer solitons in a double-layer system undergo a spontaneous-symmetry-breaking (SSB) bifurcation, producing families of asymmetric 2D solitons. The collapse occurs when the soliton's norm exceeds the norm of the Townes solitons. The SSB instability leads to dynamical symmetry breaking and spontaneous drift in the solitons.
COMMUNICATIONS IN NONLINEAR SCIENCE AND NUMERICAL SIMULATION
(2023)
Article
Chemistry, Physical
David Hochberg, Thomas Buhse, Jean-Claude Micheau, Josep M. Ribo
Summary: Investigated the chiral selectivity under non-equilibrium temperature fluctuations; used stochastic differential equation simulation method to identify the thresholds for chiral selectivity induced by chiral force; analyzed the impact of different types of fluctuations on chiral selectivity.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)
Article
Physics, Multidisciplinary
Tommaso Comparin, Fabio Mezzacapo, Martin Robert-de-Saint-Vincen, Tommaso Roscilde
Summary: This article discusses the property of spontaneous symmetry breaking in quantum spin models and demonstrates the realization of spin squeezing through adiabatic processes, providing possibilities for entanglement detection and metrological uses of quantum states.
PHYSICAL REVIEW LETTERS
(2022)
Article
Physics, Fluids & Plasmas
Hai-Jun Zhou, Qinyi Liao
Summary: The planted p-spin interaction model exhibits a microcanonical polarized phase at intermediate energy densities, with a discontinuous transition from the paramagnetic phase. This transition serves as a mechanism to evade spin-glass traps, and is accelerated by a restart strategy of microcanonical random walk. Additionally, an unsupervised learning problem is proposed for inferring the planted ground state from microcanonically sampled configurations.
Article
Materials Science, Multidisciplinary
Ming Xie, Sankar Das Sarma
Summary: The recent experimental discovery of flavor symmetry breaking metallic phases in Bernal-stacked bilayer graphene indicates the strong interaction between electrons near the top (bottom) of its valence (conduction) band. Superconductivity is observed in between these symmetry breaking phases when the graphene bilayer is subjected to a small in-plane magnetic field or is in close proximity to a monolayer WSe2 substrate. This study investigates the correlated nature of band edge electrons, obtaining the quantum phase diagram of their many-body ground states by considering the impact of proximity-induced spin-orbit coupling.
Article
Chemistry, Multidisciplinary
Yushuo Xu, Yuanyuan Wang, Shuhua Wang, Shiqiang Yu, Baibiao Huang, Ying Dai, Wei Wei
Summary: Breaking the time-reversal symmetry has been the focus of valleytronic research to achieve valley polarization, but it has also led to inevitable drawbacks. This study demonstrates a novel valley physics by lowering the crystalline symmetry instead of breaking the time reversal symmetry, showing that a spontaneous structure distortion can cause considerably large valley polarization. The study discusses the physics of valley-orbital coupling, valley-orbital-layer coupling, valley-contrasting linear dichroism, and interlayer exciton valleytronics.
Article
Optics
Long-Gang Huang, Xuanchen Zhang, Yanzhen Wang, Zhenxing Hua, Yuanjiang Tang, Yong-Chun Liu
Summary: Spin squeezing is crucial for quantum metrology and quantum information science, but its generation faces challenges due to the lack of squeezing interactions in existing physical systems. In this study, we propose a universal scheme to generate spin squeezing in coupled spin models with collective spin-spin interactions. We can transform the coupled spin interactions into squeezing interactions and achieve extreme squeezing with Heisenberg-limited measurement precision scaling as 1/N for N particles. Only constant and continuous driving fields are required, making it accessible for current realistic experiments. This work greatly expands the systems capable of generating Heisenberg-limited spin squeezing, with broad applications in quantum precision measurement.
Article
Physics, Multidisciplinary
Giovanni I. Martone, Nicolas Cherroret
Summary: This study investigates the interplay between intrinsic spin-orbit coupling and nonlinear photon-photon interactions in a nonparaxial, elliptically polarized fluid of light propagating in a bulk Kerr medium. The results show that when the nonlinear interactions induce birefringence, their interplay with spin-orbit coupling leads to interference between the two polarization components of the fluid, breaking translation symmetry along the propagation direction. This phenomenon results in a Floquet band structure in the Bogoliubov spectrum and characteristic oscillations of intensity correlations.
PHYSICAL REVIEW LETTERS
(2023)
Article
Physics, Multidisciplinary
Giovanni I. Martone, Nicolas Cherroret
Summary: We investigate the interaction between intrinsic spin-orbit coupling and nonlinear photon-photon interactions in a nonparaxial, elliptically polarized fluid of light propagating in a bulk Kerr medium. The interplay between the nonlinear interactions and spin-orbit coupling leads to an interference between the polarization components of the fluid with different wave vectors, resulting in the breaking of translation symmetry. This phenomenon gives rise to a Floquet band structure and characteristic oscillations in the intensity correlations of the fluid.
PHYSICAL REVIEW LETTERS
(2023)
Article
Engineering, Mechanical
Mateus C. P. dos Santos, Wesley B. Cardoso
Summary: The paper analyzes the spontaneous symmetry breaking induced by a specific component in a linearly coupled binary Bose-Einstein condensate. Through numerical simulations, symmetric and asymmetric ground states are obtained, and induced asymmetry in the partner field is observed, demonstrating the influence of linear coupling on the balance between atomic species and the appearance of Josephson and SSB phases.
NONLINEAR DYNAMICS
(2023)
Article
Nanoscience & Nanotechnology
Junji Fujimoto, Florian Lange, Satoshi Ejima, Tomonori Shirakawa, Holger Fehske, Seiji Yunoki, Sadamichi Maekawa
Summary: By utilizing response theory, the paper calculates the charge current vortex generated by spin pumping at a point-like contact in a system with Rashba spin-orbit coupling. The oscillatory behavior of the charge current as a function of distance from the spin pumping source is observed, which is supported by numerical simulations. The introduction of the SOC Hamiltonian on the lattice as the generator of the spin current is a significant aspect of their calculations.
Article
Quantum Science & Technology
Kashif Ammar Yasir, Lin Zhuang, Wu-Ming Liu
Summary: We investigate topological nonlinear optics with spin-orbit coupled Bose-Einstein condensate in a cavity and demonstrate different types of optical transparencies and the formation of topological edge states through quantum interference. These findings are significant for topological photonics and their application in quantum computation.
NPJ QUANTUM INFORMATION
(2022)
Article
Chemistry, Physical
Kaho Nakatani, Masahiro Higashi, Hirofumi Sato
Summary: This paper presents a methodology for analyzing chemical bonds in molecules using spin correlations in the electronic wave function. By introducing spin correlation functions using biorthogonal second quantization, the method can extract local singlet and local triplet elements. The relationship between these spin correlations and traditional chemical concepts is clarified, and the analysis method is numerically verified through chemical reactions.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Physics, Multidisciplinary
Hirokazu Tsunetsugu, Hiroaki Kusunose
Summary: We have developed a microscopic theory on the energy dispersion of phonons in chiral crystals and have shown that the splitting of sound velocity of acoustic phonons with opposite crystal angular momenta must be zero. We have also derived a formula for the k-linear splitting of chiral optical phonons. In addition, we have found that certain types of antisymmetric interactions of atomic displacements are not allowed in microscopic Hamiltonians for chiral phonons.
JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN
(2023)
Article
Chemistry, Medicinal
Kyosuke Ishito, Huiling Mao, Kaya Kobayashi, Yusuke Kousaka, Yoshihiko Togawa, Hiroaki Kusunose, Jun-ichiro Kishine, Takuya Satoh
Summary: Recently, the study of chiral phonons, which possess angular and pseudoangular momenta, has gained significant attention. The detection of peak splitting in circularly polarized Raman spectroscopy provides evidence for the presence of chiral phonons in chiral crystals. This study presents observation of chiral phonons in a unary crystal, Te, and confirms the conservation law of pseudoangular momentum in Raman scattering, which determines the handedness of chiral crystals. The true chirality of the phonons is evaluated using a measure similar to an electric toroidal monopole.
Article
Materials Science, Multidisciplinary
Satoru Hayami
Summary: In this study, the multiple-Q instability under tetragonal single-ion anisotropy is theoretically investigated. Simulated annealing for a spin model with momentum-resolved interaction and fourth-order inplane single-ion anisotropy on a square lattice reveals various field-induced double-Q states in the ground state due to the interplay between competing exchange interactions in momentum space and single-ion anisotropy. The emergence of a double-Q vortex crystal is particularly observed when the interactions at high-harmonic wave vectors are comparable to those at wave vectors with dominant contributions. These results highlight the significance of magnetic anisotropy in centrosymmetric magnets for the multiple-Q instability.
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
Satoru Hayami, Yasuyuki Kato
Summary: We numerically study the stabilization mechanisms of skyrmion crystals in itinerant centrosymmetric tetragonal magnets under thermal fluctuations and external magnetic field. By employing a efficient steepest descent method, we construct the magnetic field-temperature phase diagrams of the effective spin model based on a two-dimensional square lattice. Our results show that a square-type skyrmion crystal can be stabilized by high-harmonic wave-vector interaction or biquadratic interaction under an external magnetic field. We also find other stable multiple-Q states in the phase diagram.
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
(2023)
Article
Physics, Multidisciplinary
Satoru Hayami, Satoshi Tsutsui, Hiroki Hanate, Nobumoto Nagasawa, Yoshitaka Yoda, Kazuyuki Matsuhira
Summary: We theoretically investigate cluster multipole orderings composed of atomic high-rank multipole moments in the 5d-electron compound Ca5Ir3O12. Our analysis suggests that the intermediate-temperature phase in Ca5Ir3O12 can be attributed to a 120 degrees-type ordering of the electric quadrupole, which corresponds to cluster electric toroidal dipole ordering with the electric ferroaxial moment. We also propose that the low-temperature phase in Ca5Ir3O12 can be regarded as a coexisting state with cluster electric toroidal dipole and cluster magnetic toroidal quadrupole.
JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN
(2023)
Letter
Physics, Multidisciplinary
Akane Inda, Satoru Hayami
Summary: An electric toroidal dipole (ETD) moment is studied for its unconventional transverse responses and its ordered state under a tetragonal crystalline electric field. A third-order transverse magnetic susceptibility and spin-orbital entanglement are found to contribute to large transverse responses.
JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN
(2023)
Article
Physics, Multidisciplinary
Satoru Hayami
Summary: We theoretically propose the generation of an antiferro skyrmion crystal (AF-SkX) in a synthetic bilayer antiferro-magnetic system under an external magnetic field. The interplay among the layer-dependent Dzyaloshinskii-Moriya interaction, the easy-plane single-ion anisotropy, the interlayer exchange interaction, and the in-plane magnetic field leads to the instability toward the AF-SkX. Our results provide a guideline to experimentally search for the AF-SkX in bulk and layered materials.
JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN
(2023)
Article
Materials Science, Multidisciplinary
Satoru Hayami, Ryota Yambe
Summary: We investigate the instability towards a skyrmion crystal (SkX) in noncentrosymmetric cubic magnets and compare the differences between O, T, and Td point groups. Our results show that systems under O and T point groups exhibit two types of SkXs depending on the magnetic field direction, while systems under Td point group do not show such instability. The difference can be explained by the momentum-dependent Dzyaloshinskii-Moriya interaction. Additionally, we find that the SkX instability can occur in systems under Td point group when considering the additional effect of uniaxial strain. The present study provides rich topological spin textures in three-dimensional systems that are sensitive to magnetic field direction and point group symmetry.
Article
Materials Science, Multidisciplinary
Hiroaki Kusunose, Rikuto Oiwa, Satoru Hayami
Summary: We have developed a symmetry-adapted modeling procedure for molecules and crystals, which can systematically generate the complete symmetry-adapted multipole basis set to describe electronic degrees of freedom. By expressing the Hamiltonian in terms of linear combinations of these bases, we can determine the model parameters to reproduce electronic structures. This method provides a fundamental basis for symmetry-based analysis in materials science and complements the standard Wannier tight-binding modeling.
Article
Materials Science, Multidisciplinary
Ryota Yambe, Satoru Hayami
Summary: This article focuses on the classification of momentum-dependent anisotropic exchange interactions in cubic-lattice systems and the construction of effective spin models for different symmetries. By performing simulated annealing, the authors demonstrate that the symmetric anisotropic exchange interaction is the origin of multiple-Q states.
Article
Materials Science, Multidisciplinary
Akimitsu Kirikoshi, Satoru Hayami
Summary: We investigate the intrinsic nonlinear anomalous Hall effect (INAHE) in space-time (PT) symmetric antiferromagnetic metals. The INAHE is characterized by an asymmetric and nondissipative part of the second-order electric conductivity tensor in the clean limit. The emergence of the INAHE is due to active odd-parity magnetic quadrupoles or magnetic toroidal dipoles under magnetic orderings.
Article
Materials Science, Multidisciplinary
Ryota Yambe, Satoru Hayami
Summary: In this study, we theoretically explore the synergy between spin, charge, and sublattice degrees of freedom in itinerant magnets and discover a variety of topological spin textures classified into three types: ferrochiral, antiferrochiral, and ferrichiral skyrmion crystals. These findings reveal the potential of itinerant honeycomb magnets to host numerous skyrmion crystals and emergent phenomena.
Article
Materials Science, Multidisciplinary
Yuki Yanagi, Hiroaki Kusunose, Takuya Nomoto, Ryotaro Arita, Michi-To Suzuki
Summary: We propose a systematic method for generating symmetry-adapted magnetic structures to analyze complex modulated magnetic structures. The method extends the generation scheme based on multipole expansion, which was previously only applicable for k = 0. By mapping the multipole magnetic alignments to the periodic crystal structure with the phase factor for wave vector k, symmetry-adapted magnetic structures with ordering vector k can be obtained. This method provides all magnetic bases compatible with irreducible representations under a k group for a given crystal structure and wave vector k.
Article
Materials Science, Multidisciplinary
Satoru Hayami
Summary: In this study, a topologically nontrivial double-Q state with a net spin scalar chirality on a two-dimensional square lattice is investigated. Unconventional noncoplanar spin textures distinct from skyrmion crystal are obtained by the double-Q spiral superposition of ordering wave vectors located at the Brillouin zone boundary. The stability of this double-Q state is achieved through the interplay among the easy-axis anisotropic interaction, high-harmonic wave-vector interaction, and external magnetic field. When the Fermi level is located in the band gaps, the double-Q state becomes a Chern insulating state with a quantum Hall conductivity. This study provides a new platform for realizing topological magnetic states other than skyrmion crystals by focusing on the symmetry of constituent ordering wave vectors in momentum space.
Article
Materials Science, Multidisciplinary
Satoru Hayami
Summary: We theoretically investigate electronic orderings with the electric axial moment in the zigzag-chain system without breaking spatial inversion and time-reversal symmetries. We elucidate the role of local odd-parity hybridization in noncentrosymmetric lattice structures based on symmetry and microscopic model analyses. Our results show that the odd-parity crystalline electric field induces an effective coupling between the electric dipole and electric toroidal dipole, resulting in the induction of staggered and uniform components of the electric axial moment. We also demonstrate that uniform electric quadrupole ordering accompanies uniform electric axial moment, and discuss the transverse magnetization as a consequence of the orderings.
