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Domain wall problem in the quantum XXZ chain and semiclassical behavior close to the isotropic point

by Grégoire Misguich, Nicolas Pavloff, Vincent Pasquier

Submission summary

As Contributors: Grégoire Misguich · Nicolas Pavloff
Arxiv Link: https://arxiv.org/abs/1905.08756v1
Date submitted: 2019-05-22
Submitted by: Misguich, Grégoire
Submitted to: SciPost Physics
Domain(s): Theor. & Comp.
Subject area: Condensed Matter Physics - Theory

Abstract

We study the dynamics of a spin-1/2 XXZ chain which is initially prepared in a domain-wall state. We compare the results of time-dependent Density Matrix Renormalization Group simulations with those of an effective description in terms of a classical anisotropic Landau-Lifshitz (LL) equation. Numerous quantities are analyzed: magnetization (x, y and z components), energy density, energy current, but also some spin-spin correlation functions or entanglement entropy in the quantum chain. Without any adjustable parameter a quantitative agreement is observed between the quantum and the LL problems in the long time limit, when the models are close to the isotropic point. This is explained as a consequence of energy conservation. At the isotropic point the mapping between the LL equation and the nonlinear Schrödinger equation is used to construct a variational solution capturing several aspects of the problem.

Current status:
Editor-in-charge assigned

Submission & Refereeing History

Submission 1905.08756v1 on 22 May 2019

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