Studies of non-magnetic impurities in the spin-1/2 Kagome Antiferromagnet

TL;DR

This paper investigates how non-magnetic impurities affect local magnetic properties in a spin-1/2 Kagome antiferromagnet, combining high-temperature calculations and Dirac spin liquid models to align with experimental NMR data.

Contribution

It provides a comprehensive analysis of impurity effects using high-temperature series and Dirac spin liquid theory, bridging experimental observations and theoretical models.

Findings

Local susceptibility calculations match NMR data

Impurities induce inhomogeneous magnetic responses

Dirac spin liquid model explains low-temperature behavior

Abstract

Motivated by recent experiments on ZnCu$_3$(OH)$_6$Cl$_2$, we study the inhomogeneous Knight shifts (local susceptibilities) of spin 1/2 Kagome antiferromagnet in the presence of nonmagnetic impurities. Using high temperature series expansion, we calculate the local susceptibility and its histogram down to about T=0.4J. At low temperatures, we explore a Dirac spin liquid proposal and calculate the local susceptibility in the mean field and beyond mean field using Gutzwiller projection, finding the overall picture to be consistent with the NMR experiments.