μSR spectroscopy: A local probe of magnetic moments

Abstract

μSR (muon spin relaxation, rotation, or resonance) is an experimental technique to investigate the electromagnetic properties of materials by using a secondary muon beam produced by a cyclotron or a linear accelerator. μSR is based on the implantation of spin-polarized muons into matter and the detection of local magnetic fields and spin fluctuations. Due to the specificity of the muon, the μSR technique is an extremely sensitive way to probe very weak magnetic moments, allowing both static and dynamic magnetic behaviors to be investigated. μSR has a wide variety of applications for characterizing magnetic materials, superconductors, free radicals, topological insulators, heavy fermion systems, and frustrated quantum magnetic systems. In this paper, we describe the basic principles of μSR spectroscopy and then present our recent μSR results for quantum magnets.