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We provide a topological understanding on phonon Hall effect in dielectrics with Raman spinphonon coupling. A general expression for phonon Hall conductivity is obtained in terms of the Berry curvature of band structures. We find a…

Materials Science · Physics 2011-01-28 Lifa Zhang , Jie Ren , Jian-Sheng Wang , Baowen Li

A Kerr nonlinear oscillator (KNO) supports a pair of steady eigenstates, coherent states with opposite phases, that are good for the encoding of continuous variable qubit basis states. Arbitrary control of the KNO confined within the steady…

Quantum Physics · Physics 2024-07-16 Juan Lin , Shou-Bang Yang , Fan Wu , Zhen-Biao Yang

We show that topological transitions in electronic spin transport are feasible by a controlled manipulation of spin-guiding fields. The transitions are determined by the topology of the fields texture through an effective Berry phase…

In this work, which is based on spin-2 vectors and traceless spin-2 tensors, an effective Hamiltonian is constructed with a linearly dispersive five-fold degenerate point with spin-2 vector-momentum couplings. For the model without spin-2…

Quantum Gases · Physics 2019-06-26 Cheng Feng , Qiang Wang , S. N. Zhu , Hui Liu

Noncollinear magnetic states in clusters are studied by using the single-band Hubbard Hamiltonian. The unrestricted Hartree-Fock (UHF) approximation is considered without imposing any symmetry constraints neither to the size or orientation…

Strongly Correlated Electrons · Physics 2009-10-31 Miguel A. Ojeda , J. Dorantes-Davila , G. M. Pastor

Antiferromagnets (AFMs), in contrast to ferromagnets, show a nontrivial magnetic structure with zero net magnetization. However, they share a number of spintronic effects with ferromagnets, including spin-pumping and spin transfer torques.…

Mesoscale and Nanoscale Physics · Physics 2015-05-06 Gomonay Olena

The spin Nernst effect, an antisymmetric response of a spin current to a temperature gradient, has attracted attention as spin transport phenomenon arising from the topologically nontrivial band structure of carriers. This effect can occur…

Strongly Correlated Electrons · Physics 2025-08-12 Shinnosuke Koyama , Joji Nasu

We predict an in-plane, or hidden, Berry curvature (BC) for magnons in electrically insulating quasi-2D magnets and demonstrate that the hidden magnon Berry curvature (HMBC) gives rise to a previously unrecognized form of vertical,…

Mesoscale and Nanoscale Physics · Physics 2025-11-26 Atul Rathor , Sahanawaj Akhtar , Arijit Haldar

The eigenvalues of a parameter-dependent Hamiltonian matrix form a band structure in parameter space. In such $N$-band systems, the quantum geometric tensor (QGT), consisting of the Berry curvature and quantum metric tensors, is usually…

Other Condensed Matter · Physics 2021-08-18 Ansgar Graf , Frédéric Piéchon

The anomalous Hall, Nernst and thermal Hall coefficients of Fe$_{3-x}$GeTe$_2$ display several features upon cooling, like a reversal in the Nernst signal below $T = 50$ K pointing to a topological transition (TT) associated to the…

Berry curvature is a fundamental element to characterize topological quantum physics, while a full measurement of Berry curvature in momentum space was not reported for topological states. Here we achieve two-dimensional Berry curvature…

The coupling between the spin and momentum degrees of freedom due to spin-orbit interactions (SOI) suggests that the strength of the latter can be modified by controlling the motion of the charge carriers. In this paper, we investigate how…

Mesoscale and Nanoscale Physics · Physics 2022-06-08 Zhuo Bin Siu , Seng Ghee Tan , Mansoor B. A. Jalil

The structural, electronic and magnetic properties of small ${\rm Fe}_m {\rm Rh}_n$ clusters having $N = m+n \leq 8$ atoms are studied in the framework of a generalized-gradient approximation to density-functional theory. For $N = m+n \leq…

Materials Science · Physics 2012-01-31 Junais Habeeb Mokkath , G. M. Pastor

The Korringa-Kohn-Rostoker Green (KKR) function method for non-collinear magnetic structures was applied on Mn and Cr ad-clusters deposited on the Ni(111) surface. By considering various dimers, trimers and tetramers, a large amount of…

Materials Science · Physics 2015-06-25 Samir Lounis , Phivos Mavropoulos , Rudolf Zeller , Peter H. Dederichs , Stefan Blügel

Magnetic energy of simple cubic structured ferromagnetic films with 10 to 50 spin layers was determined using third order perturbed Heisenberg Hamiltonian. By plotting 3-D plot of energy versus angle and stress induced anisotropy, the…

Materials Science · Physics 2017-08-11 N. U. S. Yapa , P. Samarasekara

Recent advances in nanoscience have raised interest in the minimum bit size required for classical information storage, i.e. for bistability with suppressed quantum tunnelling and energy barriers that exceed ambient temperatures. In the…

Materials Science · Physics 2015-06-25 Tor O. Strandberg , Carlo. M. Canali , Allan H. MacDonald

The ground state properties and neutron structure factor for the two-dimensional antiferromagnet on the triangular lattice, with uni-directional anisotropy in the nearest-neighbor exchange couplings and a weak Dzyaloshinskii-Moriya (DM)…

Strongly Correlated Electrons · Physics 2009-11-11 Denis Dalidovich , Rastko Sknepnek , A. John Berlinsky , Junhua Zhang , Catherine Kallin

We derive an approximate expression for the Gilbert damping coefficient \alpha_G of itinerant electron ferromagnets which is based on their description in terms of spin-density-functional-theory (SDFT) and Kohn-Sham quasiparticle orbitals.…

Mesoscale and Nanoscale Physics · Physics 2015-05-13 Ion Garate , Allan H. MacDonald

Band topology of anomalous quantum Hall insulators can be precisely addressed by computing Chern numbers of constituent non-degenerate bands that describe quantized, Abelian Berry flux through two-dimensional Brillouin zone. Can Chern…

Chiral antiferromagnets are currently considered for broad range of applications in spintronics, spin-orbitronics and magnonics. In contrast to the established approach relying on materials screening, the anisotropic and chiral responses of…

Strongly Correlated Electrons · Physics 2022-06-16 Oleksandr V. Pylypovskyi , Yelyzaveta A. Borysenko , Jürgen Fassbender , Denis D. Sheka , Denys Makarov