Finite temperature Drude weight of the one dimensional spin 1/2 Heisenberg model}

TL;DR

This paper uses Bethe ansatz to analyze the finite temperature Drude weight in the 1D spin-1/2 Heisenberg model, revealing its temperature dependence and behavior at the isotropic point.

Contribution

It provides a detailed analysis of the temperature dependence of the Drude weight in the Heisenberg model using Bethe ansatz, highlighting its vanishing at the isotropic point.

Findings

Drude weight decreases monotonically with temperature for 0<Delta<1

It approaches the zero temperature value with a power law

Drude weight vanishes at finite temperatures for Delta=1

Abstract

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<Delta< 1, it approaches the zero temperature value with a power law and it appears to vanish for all finite temperatures at the isotropic Delta=1 point.