Local Magnetic Susceptibility of the Positive Muon in the Quasi 1D S=1/2 Antiferromagnet KCuF$_3$

TL;DR

This study uses muon spin rotation to measure local magnetic susceptibility in a quasi 1D antiferromagnet, revealing muon-induced perturbations that differ from bulk susceptibility.

Contribution

It provides the first detailed measurement of local magnetic susceptibility around a positive muon in a quasi 1D spin-1/2 antiferromagnet, highlighting muon-induced effects.

Findings

Identified two distinct muon sites with different temperature-dependent shifts.

Observed that the local susceptibility differs from the bulk magnetic susceptibility.

Detected muon-induced perturbations affecting the spin chain.

Abstract

We report muon spin rotation measurements of the local magnetic susceptibility around a positive muon in the paramagnetic state of the quasi one-dimensional spin 1/2 antiferromagnet KCuF$_3$. Signals from two distinct sites are resolved which have a temperature dependent frequency shift which is different than the magnetic susceptibility. This difference is attributed to a muon induced perturbation of the spin 1/2 chain.