Temperature dependence of uniform static magnetic susceptibility in a two-dimensional quantum Heisenberg antiferromagnetic model

TL;DR

This paper develops a perturbation spin-wave theory for 2D quantum Heisenberg antiferromagnets to accurately compute the uniform static magnetic susceptibility across all temperatures, resolving previous divergence issues.

Contribution

It introduces a refined spin-wave approach that removes artificial phase transition divergences and aligns well with numerical simulations for the susceptibility.

Findings

Susceptibility shows linear temperature dependence at low T

Smooth crossover in intermediate temperature range

Curie law behavior at high T

Abstract

A perturbation spin-wave theory for the quantum Heisenberg antiferromagnets on a square lattice is proposed to calculate the uniform static magnetic susceptibility at finite temperatures, where a divergence in the previous theories due to an artificial phase transition has been removed. To the zeroth order, the main features of the uniform static susceptibility are produced: a linear temperature dependence at low temperatures and a smooth crossover in the intermediate range and the Curie law at high temperatures. When the leading corrections from the spin-wave interactions are included, the resulting spin susceptibility in the full temperature range is in agreement with the numerical quantum Monte Carlo simulations and high-temperature series expansions.