Temperature dependent spatial oscillations in the correlations of the XXZ spin chain

TL;DR

This paper investigates how temperature influences the spatial oscillations in correlations of the XXZ spin chain, revealing temperature-dependent incommensurate oscillatory behavior at positive temperatures.

Contribution

It provides a numerical analysis of the correlation functions in the XXZ chain, uncovering temperature-dependent oscillations in the massless attractive regime.

Findings

Correlation functions exhibit oscillatory behavior at certain temperatures.

The oscillation period varies with temperature.

Oscillations are incommensurate and depend on temperature.

Abstract

We study the correlation $<\sigma^z_0\sigma^z_n>$ for the XXZ chain in the massless attractive (ferromagnetic) region at positive temperatures by means of a numerical study of the quantum transfer matrix. We find that there is a range of temperature where the behavior of the correlation for large separations is oscillatory with an incommensurate period which depends on temperature.