The Experts below are selected from a list of 252 Experts worldwide ranked by ideXlab platform
X Zotos - One of the best experts on this subject based on the ideXlab platform.
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a tba approach to thermal transport in the xxz Heisenberg Model
Journal of Statistical Mechanics: Theory and Experiment, 2017Co-Authors: X ZotosAbstract:It is shown that the Bethe ansatz formulation of the easy-plane 1D Heisenberg Model thermodynamics (TBA) by Takahashi and Suzuki and the subsequent analysis of the spin Drude weight, also reproduces the thermal Drude weight and magnetothermal coefficient obtained by the Quantum Transfer Matrix method (QTM). It can also be extended to study the far-out of equilibrium energy current generated at the interface between two semi-infinite chains held at different temperatures.
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finite temperature drude weight of the one dimensional spin 1 2 Heisenberg Model
Physical Review Letters, 1999Co-Authors: X ZotosAbstract:Using the Bethe ansatz method, the zero frequency contribution (Drude weight) to the spin current correlations is analyzed for the easy plane antiferromagnetic Heisenberg Model. The Drude weight is a monotonically decreasing function of temperature for all 0
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Spin and energy correlations in the one dimensional spin- Heisenberg Model
Journal of Physics: Condensed Matter, 1998Co-Authors: F Naef, X ZotosAbstract:In this paper, we study the spin and energy dynamic correlations of the one-dimensional spin- Heisenberg Model, using mostly exact diagonalization numerical techniques. In particular, observing that the uniform spin and energy currents decay to finite values at long times, we argue for the absence of spin and energy diffusion in the easy plane anisotropic Heisenberg Model.
Roderich Moessner - One of the best experts on this subject based on the ideXlab platform.
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quantum dynamics of the square lattice Heisenberg Model
Physical Review B, 2018Co-Authors: Ruben Verresen, Frank Pollmann, Roderich MoessnerAbstract:Despite nearly a century of study of the $S=1/2$ Heisenberg Model on the square lattice, there is still disagreement on the nature of its high-energy excitations. By tuning toward the Heisenberg Model from the exactly soluble Ising limit, we find that the strongly attractive magnon interactions of the latter naturally account for a number of spectral features of the Heisenberg Model. This claim is backed up both numerically and analytically. Using the density matrix renormalization group method, we obtain the dynamical structure factor for a cylindrical geometry, allowing us to continuously connect both limits. Remarkably, a semi-quantitative description of certain observed features arises already at the lowest non-trivial order in perturbation theory around the Ising limit. Moreover, our analysis uncovers that high-energy magnons are localized on a single sublattice, which is related to the entanglement properties of the ground state.
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dynamics of the kitaev Heisenberg Model
Physical Review Letters, 2017Co-Authors: Matthias Gohlke, Ruben Verresen, Roderich Moessner, Frank PollmannAbstract:: We introduce a matrix-product state based method to efficiently obtain dynamical response functions for two-dimensional microscopic Hamiltonians. We apply this method to different phases of the Kitaev-Heisenberg Model and identify characteristic dynamical features. In the ordered phases proximate to the spin liquid, we find significant broad high-energy features beyond spin-wave theory, which resemble those of the Kitaev Model. This establishes the concept of a proximate spin liquid, which was recently invoked in the context of inelastic neutron scattering experiments on α-RuCl_{3}. Our results provide an example of a natural path for proximate spin liquid features to arise at high energies above a conventionally ordered state, as the diffuse remnants of spin-wave bands intersect to yield a broad peak at the Brillouin zone center.
Bernd Rosenow - One of the best experts on this subject based on the ideXlab platform.
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unconventional pairing and electronic dimerization instabilities in the doped kitaev Heisenberg Model
Physical Review B, 2014Co-Authors: Daniel D Scherer, Michael M Scherer, G Khaliullin, Carsten Honerkamp, Bernd RosenowAbstract:Using the functional renormalization group approach this paper obtains the rich phase diagram of the Kitaev-Heisenberg Model on the honeycomb lattice which describes Na${}_{2}$IrO${}_{3}$.
Takami Tohyama - One of the best experts on this subject based on the ideXlab platform.
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ground state phase diagram of the kitaev Heisenberg Model on a kagome lattice
Physical Review B, 2018Co-Authors: Katsuhiro Morita, Masanori Kishimoto, Takami TohyamaAbstract:The Kitaev-Heisenberg Model on the honeycomb lattice has been studied for the purpose of finding exotic states such as quantum spin liquid and topological orders. On the kagome lattice, in spite of a spin-liquid ground state in the Heisenberg Model, the stability of the spin-liquid state has hardly been studied in the presence of the Kitaev interaction. Therefore, we investigate the ground state of the classical and quantum spin systems of the kagome Kitaev-Heisenberg Model. In the classical system, we obtain an exact phase diagram that has an eight-fold degenerated canted ferromagnetic phase and a subextensive degenerated Kitaev antiferromagnetic phase. In the quantum system, using the Lanczos-type exact diagnalization and cluster mean-field methods, we obtain two quantum spin-liquid phases, an eight-fold degenerated canted ferromagnetic phase similar to the classical spin system, and an eight-fold degenerated $\bf q=0$ $120^\circ$ ordered phase induced by quantum fluctuation. These results may provide a crucial clue to recently observed magnetic structures of the rare-earth-based kagome lattice compounds $A_2$RE$_3$Sb$_3$O$_{14}$ ($A$ = Mg, Zn; RE = Pr, Nd, Gd, Tb, Dy, Ho, Er, Yb).
Onofre Rojas - One of the best experts on this subject based on the ideXlab platform.
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thermal entanglement of a spin 1 2 ising Heisenberg Model on a symmetrical diamond chain
Journal of Physics: Condensed Matter, 2012Co-Authors: N S Ananikian, L N Ananikyan, Levon Chakhmakhchyan, Onofre RojasAbstract:The entanglement quantum properties of a spin-1/2 Ising?Heisenberg Model on a symmetrical diamond chain were analyzed. Due to the separable nature of the Ising-type exchange interactions between neighboring Heisenberg dimers, calculation of the entanglement can be performed exactly for each individual dimer. Pairwise thermal entanglement was studied in terms of the isotropic Ising?Heisenberg Model and analytical expressions for the concurrence (as a measure of bipartite entanglement) were obtained. The effects of external magnetic field H and next-nearest neighbor interaction Jm between nodal Ising sites were considered. The ground state structure and entanglement properties of the system were studied in a wide range of coupling constant values. Various regimes with different values of ground state entanglement were revealed, depending on the relation between competing interaction strengths. Finally, some novel effects, such as the two-peak behavior of concurrence versus temperature and coexistence of phases with different values of magnetic entanglement, were observed.