Non-magnetic impurities in two- and three- dimensional Heisenberg antiferromagnets

TL;DR

This paper investigates how non-magnetic impurities affect two- and three-dimensional Heisenberg antiferromagnets, revealing a new mechanism where magnetic moments are induced around impurities under a magnetic field, explaining experimental observations.

Contribution

It introduces a novel mechanism for impurity-induced magnetic moments in antiferromagnets under magnetic fields, supported by large-S expansion analysis.

Findings

Magnetic moments are induced around impurities in a magnetic field.

Curie-like susceptibility behavior observed below Neel temperature.

Results align with experimental data on specific compounds.

Abstract

In this paper we study in a large-S expansion effects of substituting spins by non-magnetic impurities in two- and three- dimensional Heisenberg antiferromagnets in a weak magnetic field. In particular, we demonstrate a novel mechanism where magnetic moments are induced around non-magnetic impurities when magnetic field is present. As a result, Curie-type behaviour in magnetic susceptibility can be observed well below the Neel temperature, in agreement with what is being observed in $La_2Cu_{1-x}Zn_{x}O_4$ and $Sr(Cu_{1-x}Zn_x)_2O_3$ compounds.