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Starting with general semiclassical equations of motion for electrons in the presence of electric and magnetic fields, we extend the Chambers formula to include in addition to a magnetic field, time-dependent electric fields and bands with…

Mesoscale and Nanoscale Physics · Physics 2022-04-18 Emmanouil K. Kokkinis , Garry Goldstein , Dmitry Efremov , Joseph J. Betouras

"Half moons", distinctive crescent patterns in the dynamical structure factor, have been identified in inelastic neutron scattering experiments for a wide range of frustrated magnets. In an earlier paper [H. Yan et al., Phys. Rev. B 98,…

Strongly Correlated Electrons · Physics 2025-11-03 Han Yan , Judit Romhányi , Andreas Thomasen , Nic Shannon

We generalize the concept of topological invariants for mixed states based on the ensemble geometric phase (EGP) introduced for one-dimensional lattice models to two dimensions. In contrast to the geometric phase for density matrices…

Quantum Physics · Physics 2021-09-22 Lukas Wawer , Michael Fleischhauer

Chern numbers are gaining traction as they characterize topological phases in various physical systems. However, the resilience of the system topology to external perturbations makes it challenging to experimentally investigate transitions…

Quantum Physics · Physics 2022-11-28 Junghyun Lee , Keigo Arai , Huiliang Zhang , Mark J. H. Ku , Ronald L. Walsworth

We study the magnetoelectric and magnetothermal transport properties of noncentrosymmetric metals using semiclassical Boltzmann transport formalism by incorporating the effects of Berry curvature and orbital magnetic moment. These effects…

Mesoscale and Nanoscale Physics · Physics 2021-11-03 Ojasvi Pal , Bashab Dey , Tarun Kanti Ghosh

The identification of the topological invariant of a topological system is crucial in experiments. However, due to the inherent non-Hermitian features, such determination is notably challenging in non-Hermitian systems. Here, we propose…

Mesoscale and Nanoscale Physics · Physics 2024-01-30 Hongfang Liu , Ming Lu , Shengdu Chai , Zhi-Qiang Zhang , Hua Jiang

The Chern topological numbers of a material system are traditionally written in terms of the Berry curvature which depends explicitly on the material band structure and on the Bloch eigenwaves. Here, we demonstrate that it is possible to…

Optics · Physics 2018-04-04 Mário G. Silveirinha

In a magnetic texture, the spin of a conduction electron is forced to be aligned to the localized moment. As a result, the topology of the magnetic texture affects the electron dynamics in nontrivial ways. A representative example is the…

Mesoscale and Nanoscale Physics · Physics 2022-12-22 Hidetoshi Masuda , Takeshi Seki , Jun-ichiro Ohe , Yoichi Nii , Koki Takanashi , Yoshinori Onose

We theoretically investigate a nonlinear spin Hall effect in $\mathcal{PT}$-symmetric antiferromagnetic metals, which serve as an efficient spin current generator. We elucidate that an emergent spin-dependent Berry curvature dipole is a…

Mesoscale and Nanoscale Physics · Physics 2022-09-23 Satoru Hayami , Megumi Yatsushiro , Hiroaki Kusunose

We study the relation between Chern numbers and Quantum Phase Transitions (QPT) in the XY spin-chain model. By coupling the spin chain to a single spin, it is possible to study topological invariants associated to the coupling Hamiltonian.…

Strongly Correlated Electrons · Physics 2009-10-09 H. A. Contreras , A. F. Reyes-Lega

We present measurements of a topological property, the Chern number ($C_\mathrm{1}$), of a closed manifold in the space of two-level system Hamiltonians, where the two-level system is formed from a superconducting qubit. We manipulate the…

We propose to measure band topology via quantized drift of Bloch oscillations in a two-dimensional Harper-Hofstadter lattice subjected to tilted fields in both directions. When the difference between the two tilted fields is large, Bloch…

Quantum Gases · Physics 2021-10-04 Bo Zhu , Shi Hu , Honghua Zhong , Yongguan Ke

Topologically ordered phase has emerged as one of most exciting concepts that not only broadens our understanding of phases of matter, but also has been found to have potential application in fault-tolerant quantum computation. The direct…

Quantum Physics · Physics 2016-06-01 Zhihuang Luo , Chao Lei , Jun Li , Xinfang Nie , Zhaokai Li , Xinhua Peng , Jiangfeng Du

By considering an extended double-exchange model with spin-orbit coupling (SOC), we derive a general form of the Berry phase $\gamma$ that electrons pick up when moving around a closed loop. This form generalizes the well-known result valid…

Strongly Correlated Electrons · Physics 2020-01-29 Shang-Shun Zhang , Hiroaki Ishizuka , Hao Zhang , Gábor B. Halász , Cristian D. Batista

Higher-dimensional Hilbert spaces in quantum simulation, as in all quantum science, expand the range of accessible phenomena. In this work, we experimentally realize a synthetic monopole using an ultracold spin-1 ensemble, where the…

Density waves conventionally describe the periodic modulation of charge or spin, yet the spatial modulation of electronic geometry has remained elusive. Here, we report subtle micrometer-scale spatial modulations of the magneto-optical Kerr…

Strongly Correlated Electrons · Physics 2026-05-05 Weihang Lu , Camron Farhang , Yuchuan Yao , Pratap Pal , Hao Zhang , Shaofeng Han , Shi-Zeng Lin , Chang-Beom Eom , Jing Xia

Altermagnetism has been detected in several materials using spin-sensitive probes. These measurements require rather complex setups that make it challenging to track variations in altermagnetic order, e.g., to identify a temperature-tuned…

Mesoscale and Nanoscale Physics · Physics 2025-07-09 T. Farajollahpour , R. Ganesh , K. V. Samokhin

We report first-principles all-electron density-functional based studies of the electronic structure, magnetic ordering and anisotropy for the V$_{15}$ molecular magnet. From these calculations, we determine a Heisenberg Hamiltonian with…

Materials Science · Physics 2009-11-07 Jens Kortus , C. Stephen Hellberg , Mark R. Pederson

The effective Hamiltonian for the linear $E\otimes e$ Jahn-Teller model describes the coupling between two electronic states and two vibrational modes in molecules or bulk crystal impurities. While in the Born-Oppenheimer approximation the…

Chemical Physics · Physics 2017-12-19 Ryan Requist , Cesar R. Proetto , E. K. U. Gross

We discuss the topological phase transition of the spin-$\frac{1}{2}$ fermionic Haldane model with repulsive on-site interaction. We show that the Berry curvature of the topological Hamiltonian, the first Chern number, and the topological…