Magnetic Impurity in the two-dimensional Heisenberg Antiferromagnet

TL;DR

This paper investigates the effects of a magnetic impurity in a 2D quantum antiferromagnet, revealing partial screening, local magnetization suppression, and local singlet formation through perturbation theory and exact diagonalization.

Contribution

It introduces a perturbative approach around strong Kondo coupling and compares it with numerical methods to analyze impurity effects in 2D antiferromagnets.

Findings

Impurity is partially screened at intermediate coupling.

Local magnetization is suppressed near the impurity.

A local singlet forms between impurity and host spins.

Abstract

We analyze the ground state properties of the two-dimensional quantum antiferromagnet with a S=1/2 Kondo impurity. Perturbation theory around the strong Kondo coupling limit is developed and the results compared with studies, based on exact diagonalization of small clusters. We find that at intermediate coupling the impurity is partially screened and the magnetization locally suppressed. A local singlet between the impurity and the host spin is formed asymptotically.