Thermodynamics of quantum spin chains with competing interactions

TL;DR

This paper investigates the thermodynamics of integrable quantum spin chains with competing interactions using the quantum transfer matrix method, deriving integral equations and analyzing ground state behavior at finite temperatures.

Contribution

It introduces a novel application of the quantum transfer matrix approach to spin chains with competing interactions, deriving integral equations for thermodynamics.

Findings

Numerical solutions for entropy as a function of magnetic field, temperature, and coupling.

Insights into the ground state diagram at low finite temperatures.

Assessment of high spin chain behavior with longer-range interactions.

Abstract

We consider integrable quantum spin chains with competing interactions. We apply the quantum transfer matrix approach to these spin chains. This allowed us to derive a set of non-linear integral equations for the thermodynamics of these spin chains. We provide numerical solution of these integral equations for the entropy as function of magnetic field, temperature and the coupling constant. This allow us to assess, at low but finite temperature, the picture describing the ground state diagram for high spin chain and longer range interchain interactions.