In this talk I will introduce the muon spin relaxation technique and its application as a local probe of the properties of quantum magnets. There will be a particular focus on layered magnetic materials that have properties consistent with a quantum spin liquid (QSL) ground state. As a point probe of spin fluctuations, the muon is well suited to studying the diffusive excitations that are associated with liquid-like states such as the QSL. Detailed studies of the temperature dependent diffusion rate of these spin excitations allow inferences to be made about the type of QSL, as well as other properties such as the location of the classical to quantum crossover and the degree of quantum entanglement of the spins.

Francis Pratt completed his physics doctorate at Oxford University in 1985 and subsequently spent time in postdoctoral positions at the Clarendon Laboratory, Oxford, and at the Institute for Materials Research, Sendai before joining the RIKEN-RAL muon facility at Rutherford Appleton Laboratory (RAL) in Oxfordshire in 1995. In 2000 he moved to the ISIS Muon Group at RAL as an instrument scientist and since 2013 he has held a position as STFC Fellow working within the ISIS Muon Group. His research interests are directed towards applications of SR in condensed matter science, with particular focus on spin liquids and other quantum materials such as organic conductors and magnets. He has published 370 research papers and is co-editor of the textbook 'Muon Spectroscopy – An Introduction'.

Please contact phweb@ust.hk should you have questions about the talk.