Low energy effective Hamiltonian for the XXZ spin chain

TL;DR

This paper derives the coupling constants for the low energy effective Hamiltonian of the XXZ spin chain and uses them to analyze thermodynamics, finite size effects, and correlation functions.

Contribution

It provides explicit coupling constants for the effective Hamiltonian and applies them to study low energy properties of the XXZ spin chain.

Findings

Coupling constants for relevant terms are explicitly derived.

Thermodynamics at low temperature and weak magnetic field are analyzed.

Finite size effects and long-distance correlation asymptotics are characterized.

Abstract

Coupling constants for the most relevant terms in the low energy effective Hamiltonian of the XXZ spin chain are derived. Using this result we study the low energy (low temperature, weak magnetic field) thermodynamics, finite size effects and subleading long distance asymptotics of correlation functions.