Transport in quasi one-dimensional spin-1/2 systems

TL;DR

This paper investigates the spin and thermal transport properties of one-dimensional quantum spin-1/2 systems, highlighting differences between integrable and nonintegrable models through numerical analysis.

Contribution

It provides a comparative numerical study of transport in integrable and nonintegrable 1D spin-1/2 systems, emphasizing the ballistic nature of thermal conductivity in integrable models.

Findings

Thermal conductivity in the XXZ chain is ballistic at finite temperatures.

Nonintegrable models show vanishing thermal conductivity.

Frequency dependence of transport coefficients varies between models.

Abstract

We present numerical results for the spin and thermal conductivity of one-dimensional (1D) quantum spin systems. We contrast the properties of integrable models such as the spin-1/2 XXZ chain against nonintegrable ones such as frustrated and dimerized chains. The thermal conductivity of the XXZ chain is ballistic at finite temperatures, while in the nonintegrable models, this quantity is argued to vanish. For the case of frustrated and dimerized chains, we discuss the frequency dependence of the transport coefficients. Finally, we give an overview over related theoretical work on intrinsic and extrinsic scattering mechanisms of quasi-1D spin systems.