Heavy Elements for Superspintronics

Materials with large spin-orbit interactions are of great interest in the field of spintronics, where they are used to generate spin-polarised currents via the spin Hall effect, and switch magnetic elements for memory and logic applications. At the same time in the field of superconductivity, spin-orbit interactions create Cooper pairs which are no longer simply spin singlet, but possess a triplet pair component with spins parallel.

Combining these two fields, an area known as superspintronics, is of intense fundamental and practical interest, since the triplet Cooper pairs can exist inside neighbouring ferromagnetic layers in a thin film heterostructure, offering the opportunity of creating spintronic devices with greatly reduced ohmic losses.

In this context, elemental uranium, the heaviest naturally occurring element, is not only superconducting, but shows a range of spin-orbit strengths depending on its crystallographic character. In Bristol we have a thin film sputtering system, unique in the UK, capable of creating not only novel crystalline states of uranium in single crystal form, but also creating high quality heterostructures with ferromagnets and other materials.

This project will leverage this equipment to investigate the low temperature properties of various U-based heterostructures and alloys to create novel electronic states of material and superspintronic devices.