Revealing Fermi surface topologies through synchrotron Compton scattering and ab initio calculations

The Fermi surface is one of the most important concepts in the physics of metals [1]. Its shape is important for understanding the properties and behaviours of a metal (e.g. magnetic order, superconductivity, charge- and spin-density waves), and measuring it is a challenging but important task.

Compton scattering, in which a photon is inelastically scattered by an electron in the material being studied, can uniquely provide access to the ground-state electronic wavefunction, and also the Fermi surface. Fermi surface measurements by Compton scattering are not limited by short electron mean free paths or by low temperatures. The experiments can be performed with, or without an applied magnetic field, and - most importantly - it probes the bulk, rather than the surface [2]. For example, our recent work on PdCrO2 was able to elucidate the role of the Fermi surface in mediating the frustrated magnetic interactions between local Cr magnetic moments [3].

The group is currently working on a diverse range of materials, including topological superconductors, high-entropy alloys, half-metallic ferromagnets, (topological) Kondo insulators and correlated oxides.

The student will have the opportunity of operating in an environment where experimental work is supported and inspired by electronic structure theory developed and executed within the group. The student would be expected to take an active role in these theoretical endeavours, which most recently have focused on being able to treat more strongly correlated electronic materials through techniques such as DMFT and GW. The project would suit someone who has a strong interest in computational theoretical condensed matter physics but would like to maintain a very close connection to experiment. As part of this project, you might also be involved with experiments at national and international facilities (such as SPring-8 in Japan).