Ballistic Transport and Boundary Resistances in Inhomogeneous Quantum Spin Chains

Overview

Journal Nat Commun

Specialty Biology

Date 2019 Oct 25

PMID 31645569

Authors

Alberto Biella

Mario Collura

Davide Rossini

Andrea De Luca

Leonardo Mazza

Affiliations

Soon will be listed here.

Abstract

Transport phenomena are central to physics, and transport in the many-body and fully-quantum regime is attracting an increasing amount of attention. It has been recently revealed that some quantum spin chains support ballistic transport of excitations at all energies. However, when joining two semi-infinite ballistic parts, such as the XX and XXZ spin-1/2 models, our understanding suddenly becomes less established. Employing a matrix-product-state ansatz of the wavefunction, we study the relaxation dynamics in this latter case. Here we show that it takes place inside a light cone, within which two qualitatively different regions coexist: an inner one with a strong tendency towards thermalization, and an outer one supporting ballistic transport. We comment on the possibility that even at infinite time the system supports stationary currents and displays a non-zero Kapitza boundary resistance. Our study paves the way to the analysis of the interplay between transport, integrability, and local defects.

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