arXiv:cond-mat/9812012 · Physical Review Letters
Temperature-Dependent Spatial Oscillations in the Correlations of the XXZ Spin Chain
K. Fabricius, Andreas Klümper, Barry M. McCoy
Abstract
We study the correlation $〈{\ensuremath{\sigma}}_{0}^{z}{\ensuremath{\sigma}}_{n}^{z}〉$ for the $\mathrm{XXZ}$ 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.