Article
Materials Science, Multidisciplinary
Qi-Hui Chen, Fei-Jie Huang, Yong-Ping Fu
Summary: In this study, we investigate the magnetic excitations of the antiferromagnetic XXZ model on a two-dimensional triangular lattice and discover the magnon valley thermal Hall effect. We demonstrate that the valley thermal Hall conductivity complies with the universal behavior proposed by Yang et al. [Phys. Rev. Lett. 124, 186602 (2020)]. Additionally, we analyze the low-energy effective theory near the valleys and find that although the dynamic matrix is non-Hermitian, the Berry curvatures are primarily determined by its Hermitian part. Moreover, our results are shown to hold generality to some extent in the Y phase of the triangular lattice. By calculating with experimental parameters, we identify Rb4Mn(MoO4)(3) as a suitable material for realizing the magnon valley thermal Hall effect.
Article
Mathematics, Applied
M. O. Sales, A. Ranciaro Neto, F. A. B. F. de Moura
Summary: We study the behavior of a single magnon excitation in a quantum Heisenberg model subjected to lattice vibrations. The Heisenberg spins are arranged in a nonlinear Morse chain with distance-dependent coupling. By numerically solving the time evolution, we explore the relationship between the magnon velocity and the spin-lattice coupling. Our findings reveal that the lattice deformation captures a significant fraction of the spin wave function, leading to a mobile magnon-lattice excitation under strong spin-lattice coupling. Additionally, we investigate the lattice deformation and magnon wave functions independently and observe solitonic characteristics in both spatial profiles.
PHYSICA D-NONLINEAR PHENOMENA
(2023)
Article
Materials Science, Multidisciplinary
A. V. Syromyatnikov
Summary: In this study, a spin-1/2 Heisenberg antiferromagnet on the triangular lattice was discussed using the bond-operator technique (BOT). It was found that high-energy collective excitations and another high-energy quasiparticle exist in the system. Quantum fluctuations considerably alter the properties of conventional magnons, and the anomalous spin dynamics observed experimentally recently cannot be described by SWT.
Article
Physics, Multidisciplinary
Katja Biswas
Summary: This article compares enhanced disconnectivity graphs for three different models of spin systems constrained to an Archimedean triangular lattice. The graphs show clear differences in structure for the three models, indicating different accessibility of ground states. The graphs can serve as a tool for understanding the difficulties faced by optimization routines and their effectiveness. Additionally, the graphs provide detailed insight into the structure of the energy landscape.
PHYSICA A-STATISTICAL MECHANICS AND ITS APPLICATIONS
(2023)
Article
Materials Science, Multidisciplinary
A. C. Duran, S. A. Osorio, M. B. Sturla
Summary: We studied the anomalous Hall effect on the antiferromagnetic coloring-triangular lattice with spin-orbit interaction. Our results show that a finite Hall conductivity occurs in the planar 120° structure with finite spin-orbit coupling, and a quantized Hall conductivity appears at global band gaps resulting from a topologically nontrivial band structure.
Article
Physics, Multidisciplinary
A. O. Scheie, E. A. Ghioldi, J. Xing, J. A. M. Paddison, N. E. Sherman, M. Dupont, L. D. Sanjeewa, Sangyun Lee, A. J. Woods, D. Abernathy, D. M. Pajerowski, T. J. Williams, Shang-Shun Zhang, L. O. Manuel, A. E. Trumper, C. D. Pemmaraju, A. S. Sefat, D. S. Parker, T. P. Devereaux, R. Movshovich, J. E. Moore, C. D. Batista, D. A. Tennant
Summary: We demonstrate the close proximity of the delafossite material KYbSe2 to the triangular-lattice Heisenberg quantum spin liquid. Using neutron scattering, we identify multipartite entanglement and analyze the magnetic-exchange couplings to confirm its proximity to the theoretical quantum spin-liquid phase. The experimental results are consistent with theoretical models, and a second-order quantum phase transition is observed.
Article
Physics, Multidisciplinary
Pardeep Kaur, Sandeep Gautam, S. K. Adhikari
Summary: We demonstrate the spontaneous generation of spatially-periodic supersolid-like super-lattice and stripe solitons in Rashba spin-orbit coupled spin-1 and spin-2 quasi-two-dimensional nonmagnetic Bose-Einstein condensates. The solitons in a weakly spin-orbit coupled spin-1 condensate are circularly-symmetric with inherent vorticity, while the solitons in an spin-orbit coupled spin-2 condensate have multiple types of circularly-symmetric shapes and can acquire a multiring structure with stronger coupling strengths. Additionally, quasi-degenerate stripe and super-lattice solitons emerge as excited stationary states for stronger spin-orbit coupling strengths.
Article
Physics, Multidisciplinary
Amal Aldarawsheh, Moritz Sallermann, Muayad Abusaa, Samir Lounis
Summary: Skyrmions are considered as the potential future of data storage due to their topologically protected spin structures. Antiferromagnetic skyrmions, consisting of two ferromagnetic solitons coupled antiferromagnetically, are predicted to have zero Magnus force, making them promising candidates for spintronic devices.
FRONTIERS IN PHYSICS
(2023)
Article
Materials Science, Multidisciplinary
Alexander Mook, Rhea Hoyer, Jelena Klinovaja, Daniel Loss
Summary: We study quantum condensed matter systems where particle number is not conserved, leading to topological anticrossings in the spectrum due to hybridization of states from different particle-number sectors. This phenomenon is observed in fully saturated spin-anisotropic quantum magnets, where single magnons hybridize with magnon bound pairs. The resulting chiral edge excitations are composite particles with mixed spin-multipolar character, showing genuine quantum mechanical effects that vanish in the classical limit. These findings have implications for intrinsic anomalous Hall-type transport, suggesting that fully polarized quantum magnets can serve as a promising platform for studying topological effects caused by hybridizations between particle-number sectors.
Article
Physics, Applied
Hantao Zhang, Ran Cheng
Summary: Recent progress in the study of magnon spin Nernst effect in collinear antiferromagnets has revealed profound topological features and inspired the exploration of topological magnons.
APPLIED PHYSICS LETTERS
(2022)
Article
Physics, Particles & Fields
Jiaju Zhang, M. A. Rajabpour
Summary: We study the entanglement content of magnon excited states in integrable spin chains and classify it in the scaling limit. We find that when the number of excited magnons is small compared to the system size, the entanglement content can be decomposed into the sum of entanglement of particular excited states in free fermionic or bosonic theories. We also conjecture a classification of the entanglement content of translational invariant free fermionic and bosonic Hamiltonians based on the entanglement content of fermionic and bosonic chains with the number operator as the Hamiltonian.
JOURNAL OF HIGH ENERGY PHYSICS
(2022)
Article
Optics
Pardeep Kaur, Sandeep Gautam, S. K. Adhikari
Summary: We studied the emergence of supersolid-like crystalline structures in a quasi-two-dimensional spin-orbit coupled spin-2 condensate. Different strengths of spin-orbit coupling and interatomic interactions led to a variety of nontrivial density patterns in the solutions.
Article
Materials Science, Multidisciplinary
Meng-Han Zhang, Dao-Xin Yao
Summary: By calculating its Berry curvature, Chern number, and edge states, we present the topology of magnons on the triangular kagome lattice (TKL). In addition to the ferromagnetic state, the TKL also hosts a ferrimagnetic ground state. Using Holstein-Primakoff boson theory and Green's function approach, we find that the TKL has a rich topological band structure compared with the kagome and honeycomb lattices. The magnon edge current allows for the calculation of thermal Hall coefficients and the orbital angular momentum correlates with the Einstein-de Haas effect.
Article
Materials Science, Multidisciplinary
Yuan Gao, Yu-Chen Fan, Han Li, Fan Yang, Xu-Tao Zeng, Xian-Lei Sheng, Ruidan Zhong, Yang Qi, Yuan Wan, Wei Li
Summary: The recently synthesized NBCP compound is found to be an ideal realization of a S = 1/2 triangular-lattice antiferromagnet with significant easy-axis spin exchange anisotropy. By combining automatic parameter searching and tensor-network simulations, a microscopic model is established to accurately describe the material's properties, fitting well with experimental data.
NPJ QUANTUM MATERIALS
(2022)
Article
Physics, Multidisciplinary
Kevin T. Geier, Giovanni Martone, Philipp Hauke, Sandro Stringari
Summary: This study proposes observable features for detecting supersolidity in harmonically trapped spin-orbit-coupled Bose-Einstein condensates, and provides signatures of Goldstone modes associated with supersolidity. The system behavior undergoes drastic changes at the critical Raman coupling, with distinctive axial breathing oscillations observed above the transition.
PHYSICAL REVIEW LETTERS
(2021)
Article
Nanoscience & Nanotechnology
Y. Miyazaki, D. Yamamoto, G. Marmorini, N. Furukawa
Summary: The phase transitions of SU(4)-symmetric tetramer systems exhibit two step-like transitions during the saturation process, with an intermediate phase being a nontrivial solid phase.
Article
Physics, Multidisciplinary
Ryui Kaneko, Ippei Danshita
Summary: This study utilizes tensor-network methods on classical computers to investigate the dynamics of the two-dimensional Bose-Hubbard model, comparing it to known limits and recent experiments. It also covers the intermediate region of moderate interactions.
COMMUNICATIONS PHYSICS
(2022)
Article
Physics, Multidisciplinary
Yuki Miyazaki, Giacomo Marmorini, Nobuo Furukawa, Daisuke Yamamoto
Summary: In this study, we investigate the quantum magnetism of atoms with four nuclear-spin components in a square optical superlattice and reveal the ground-state phase diagram and excitation spectra. Our main finding is the discovery of a nontrivial intermediate phase with a checkerboard-like arrangement.
JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN
(2022)
Article
Physics, Multidisciplinary
Hayato Motegi, Giacomo Marmorini, Nobuo Furukawa, Daisuke Yamamoto
Summary: We studied three-component SU(3) Fermi gases in a square optical lattice with population imbalance between one component and the others. At strong coupling, the system can be described by the SU(3) Heisenberg model with an external field coupling to the population imbalance. We discussed the ground state at the mean-field level and analyzed the thermal fluctuations using the semiclassical Monte Carlo method. The interplay between interactions, population imbalance, and thermal fluctuations leads to a phase transition related to the breaking of an emergent Ising symmetry, even in the absence of frustration. Possible implementations using cold alkaline-earth(-like) atoms are also discussed.
PHYSICAL REVIEW RESEARCH
(2023)
Article
Optics
Mathias Mikkelsen, Ippei Danshita
Summary: It has been discovered that noise correlations measured by time-of-flight imaging in cold-atom experiments can probe the spin structure factor in the Mott-insulating regime of SU(2) Hubbard models. In this study, the mathematical relation between noise correlations and spin structure factor in the strong-interaction limit of SU(N) Hubbard models at any integer filling was derived. Numerical calculations based on the ground states of one-dimensional SU(N) Fermi-Hubbard models for 2≤N≤6 using the density-matrix renormalization-group method confirmed this relation in the regime of strong interactions. It was shown that the deviation between actual noise correlations and those obtained from the spin structure factor scaled as (t/U)^2 for rho = 1 at intermediate and large lattice sizes.
Article
Optics
Daichi Kagamihara, Ryui Kaneko, Shion Yamashika, Kota Sugiyama, Ryosuke Yoshii, Shunji Tsuchiya, Ippei Danshita
Summary: We investigate the time-dependent Renyi entanglement entropy after a quantum quench starting from the Mott-insulating and charge-density-wave states in a one-dimensional free boson system. The second Renyi entanglement entropy is found to be the negative of the logarithm of the permanent of a matrix consisting of timedependent single-particle correlation functions. From this relation and a permanent inequality, we obtain rigorous conditions for satisfying the volume-law entanglement growth. We also succeed in calculating the time evolution of the Renyi entanglement entropy in extremely large systems by brute-force computations of the permanent. We discuss possible applications of our findings to the real-time dynamics of noninteracting bosonic systems.
Article
Materials Science, Multidisciplinary
Shimpei Goto, Ryui Kaneko, Ippei Danshita
Summary: We investigate the sampling efficiency for simulating quantum many-body systems at finite temperatures using initial sampling states generated by applying Trotter gates to random phase product states (RPPSs). The number of Trotter gate applications is proportional to the system size, making the preparation easily achievable in fault-tolerant quantum computers. When the Trotter gates are made from a nonintegrable Hamiltonian, we observe an increase in sampling efficiency with system size, indicating that almost ideal sampling of initial states can be achieved in sufficiently large systems. We also find that the sampling efficiency is comparable to that obtained by a thermal pure quantum (TPQ) state method in some cases, suggesting that chaotic Hamiltonian dynamics can transform RPPSs into an alternative to TPQ states for evaluating thermal expectation values.
Article
Materials Science, Multidisciplinary
Kazuki Okada, Hidekazu Tanaka, Nobuyuki Kurita, Daisuke Yamamoto, Akira Matsuo, Koichi Kindo
Summary: This study investigates the field-angle dependence of the magnetization process in Ba3CoSb2O9 and compares the results with other methods. The research reveals different magnetization behaviors in Ba3CoSb2O9 under different field directions, including a narrow 1/3-magnetization plateau and a high-field transition with a small magnetization jump.
Article
Optics
Mathias Mikkelsen, Ryui Kaneko, Daichi Kagamihara, Ippei Danshita
Summary: The ground-state phase diagram of the one-dimensional attractive Fermi-Hubbard model with spin-dependent hoppings and an on-site Rabi coupling is investigated using the density matrix renormalization group method. It is shown that even in the limit of one component being immobile, the pair superfluidity can be resonantly enhanced when the Rabi coupling is on the order of the interaction strength just before the system starts to strongly polarize. An effective spin-1/2 XXZ model is derived to understand the ground-state properties in the strong attraction limit.
Article
Physics, Multidisciplinary
Daisuke Yamamoto, Kotaro Bannai, Nobuo Furukawa, Carlos A. R. Sa de Melo
Summary: This study investigates the emergence of supersolid devil's staircases of spin-orbit-coupled bosons loaded in optical lattices. It is found that the spin-orbit coupling generates length scales that are commensurate to the lattice spacing, resulting in devil's staircases of supersolids. Umklapp processes are essential for the existence of commensurate supersolids.
PHYSICAL REVIEW RESEARCH
(2022)
Article
Materials Science, Multidisciplinary
X. Z. Liu, O. Prokhnenko, M. Bartkowiak, A. Gazizulina, D. Yamamoto, A. Matsuo, K. Kindo, K. Okada, N. Kurita, H. Tanaka
Summary: Spin-1/2 triangular lattice Heisenberg antiferromagnet exhibits novel spin structures and phase transitions in an applied magnetic field. In this study, magnetization and neutron scattering experiments were performed on Ba3CoSb2O9 to investigate the system with a field along the c axis. A narrow magnetization plateau and phase transitions were observed, providing insights into the spin-state evolution and phase behavior of the system in the c-axis field.
Article
Optics
Yoshihiro Machida, Ippei Danshita, Daisuke Yamamoto, Kenichi Kasamatsu
Summary: In this theoretical study, we investigate the dynamical formation of a self-bound quantum droplet in a two-component Bose-Hubbard system with an external trap potential. The behavior of the droplet can be induced by controlling the trap potential, and can be qualitatively described by an effective Ginzburg-Landau field theory.
Article
Physics, Multidisciplinary
Kazuma Nagao, Yosuke Takasu, Yoshiro Takahashi, Ippei Danshita
Summary: The study utilizes the SU(3) truncated Wigner approximation to analyze the far-from-equilibrium quantum dynamics of strongly interacting Bose gases in an optical lattice. Comparisons with exact computations show that both the SU(3) TWA and Gaussian approximation can quantitatively capture quantum dynamics on a specific timescale. However, noticeable deviations between theories and experiments indicate the need for proper consideration of the effects of spatial inhomogeneity.
PHYSICAL REVIEW RESEARCH
(2021)
Correction
Optics
Ippei Danshita, Daisuke Yamamoto, Yasuyuki Kato
