Temperature Correlations of Quantum Spins

TL;DR

This paper solves a long-standing problem by showing that the temperature correlations in the isotropic XY model are described by a tau function of the Ablowitz-Ladik PDE, providing explicit asymptotic evaluations.

Contribution

It demonstrates that the correlation functions of the 1D isotropic XY model are tau functions of the Ablowitz-Ladik PDE, offering a novel analytical approach.

Findings

Correlation functions are tau functions of Ablowitz-Ladik PDE

Explicit asymptotic expressions derived

Solved a long-standing problem in quantum spin correlations

Abstract

Isotropic XY is considered. It describes interaction of quantum spins on 1-dimesional lattice. Alternatevly one can call the model XXO Hiesenberg antiferromagnet. We solved long standing problem of evaluation of temperature corelations. We proved that correlation function of the model is $\tau $ function of Ablowitz-Ladik PDE. We explicitly evaluated asymptotics.