Unconventional superconductivity in materials with strong spin-orbit coupling and novel structures

In conventional superconductors, the superconductivity arises from an electron-phonon coupling of electrons to form Cooper pairs, with a single, s-wave, isotropic gap. In unconventional materials, the Cooper pairs may be coupled by other interactions, the pair wave function may be an odd-parity spin-triplet, or there may be multiple superconducting bands.

Unconventional superconductivity can be found in number of different classes of materials. These include superconductors with noncentrosymmetric crystal structures, i.e. systems without inversion symmetry where parity is no longer a meaningful label, in materials with strong spin-orbit coupling, e.g. those containing 4d and 5d metals, and in systems with unusual crystallographic geometries, e.g. kagome lattice superconductors. It will be these three groups of superconductors that will be the focus of this PhD research.

Polycrystalline and single crystal samples of novel superconducting materials will be prepared by different methods including the Bridgman, Czochralski and floating zone techniques. The structure and composition of the samples will be studied using x-ray diffraction and electron microscopy. The normal and superconducting state properties of these materials will be examined at low temperatures and in high magnetic fields.

As well as experiments in our laboratories, a range of neutron scattering and muon spectroscopy techniques available at national and international central facilities will be used to investigate the physics of these materials.

The research lies within the EPSRC's Physical Sciences theme Advanced Materials contributing to research areas such as Superconductivity, Condensed Matter Magnetism and Magnetic Materials and Electronic Structure. The research contributes to EPSRC Grand Challenges such as Emergence of Physics Far from Equilibrium. Long term impact may be felt in areas such as Engineering Net Zero (superconducting power transmission cables) and Transforming Health and Healthcare (MRI).