Quantum dynamics of frustrated spin systems studied with high frequency susceptibility

We investigate the magnetic spin dynamics of bulk systems as quantum effects start to become relevant at low temperature. We do this by looking at spin relaxation using a variety of experimental probes. These range from neutrons and muons, where large particle accelerators are required to produce these particles which can then map out the fundamental properties, and laboratory based equipment. At Cardiff we have developed a high frequency susceptibility probe system which can operate from 50 mK to 400 K. Your PhD would focus on investigating frustrated materials with these techniques, specifically we look at materials where emergent phenomena occur, for example in the spin ice systems we have investigated the occurrence of magnetic monopoles. This is where excitations out of the frustrated ground state create magnetic excitations that undergo a Coulomb interaction, this novel result can be used to demonstrate that Maxwells equations have a direct symmetry between electrical and magnetic charges.

In this project you will use a range of experimental techniques using dilution fridges and cryostats to probe the frequency response of the spin dynamics and then model the results based on the latest understanding in our field. You will join an existing group (2 PHD and a PDRA) and develop a range of skills covering experimental physics, modelling and project planning with opportunities to write papers and present work at international conferences. In the first 6 months of the project, training on the high frequency susceptometer, courses explaining theory of the field and use of central facilities will be given followed by 24 months of detailed research on single ion dynamics in spin ice at the quantum limit, and 12 months manuscript and thesis writing. The use of available, cutting edge equipment facilitated by dynamic weekly meetings will enable a fulfilling PhD.