Finite temperature correlation function for one-dimensional Quantum Ising model: the virial expansion

TL;DR

This paper reformulates the finite temperature two-point correlation function of the 1D Quantum Ising model as a partition function, enabling a virial expansion in soliton density to analyze thermal effects.

Contribution

It introduces a new field-theoretic representation of the correlation function, facilitating the development of a virial expansion for the model.

Findings

Removes singularities in the correlation function expression

Provides a practical framework for virial expansion analysis

Enhances understanding of thermal effects in 1D Quantum Ising model

Abstract

We rewrite the exact expression for the finite temperature two-point correlation function for the magnetization as a partition function of some field theory. This removes singularities and provides a convenient form to develop a virial expansion (the expansion in powers of soliton density).