Spin wave calculation of the field-dependent magnetization pattern around an impurity in Heisenberg antiferromagnets

TL;DR

This paper investigates how impurities affect the local magnetization in Heisenberg antiferromagnets under magnetic fields, using analytical, numerical, and quantum Monte Carlo methods to reveal universal decay patterns.

Contribution

It introduces a combined analytical and numerical spin wave approach to study impurity-induced magnetization patterns, validated by quantum Monte Carlo simulations.

Findings

Magnetization decay follows a universal form.

Overall magnetization magnitude depends on impurity size and coupling.

Results align with properties of the pure antiferromagnetic Heisenberg model.

Abstract

We consider the magnetic-field dependent spatial magnetization pattern around a general impurity embedded in a Heisenberg antiferromagnet using both an analytical and a numerical spin wave approach. The results are compared to quantum Monte Carlo simulations. The decay of the magnetization pattern away from the impurity follows a universal form which reflects the properties of the pure antiferromagnetic Heisenberg model. Only the overall magnitude of the induced magnetization depends also on the size of the impurity spin and the impurity coupling.