Topological mesoscopic superfluidity of 3He

Superfluid 3He is one of the most exciting and rich condensed matter systems we know. Over the past thirty years its intellectual impact has been felt in areas as diverse as unconventional superconductivity, cosmology and turbulence. Our recent research has taken superfluid 3He into a new regime, through its confinement on the nanoscale in well characterized nanofluidic sample chambers, exploiting new sensitive NMR techniques. The influence of confinement is profound and we expect to identify and explore new states of topological quantum matter, opening a new chapter in quantum fluids research.

In this project, we exploit superfluid 3He, known to support two distinct topological superfluid phases in bulk, establishing the new research direction of topological mesoscopic superfluidity. Under nanoscale confinement, this material provides a unique model for topological superconductivity. The subtle interplay between symmetry and topology in these materials is an open question. Our approach will be to confine 3He in precisely engineered geometries to create hybrid nanostructures, allowing a degree of control that is unprecedented. Confinement and periodic structures, with liquid pressure as a tuning parameter of Cooper pair diameter, will induce new superfluid phases, for which the order parameter symmetry will be inferred from nuclear magnetic resonance. These materials will be building blocks for hybrid mesoscopic superfluid systems.

The project is expected to lead to fundamental insights into topological quantum matter and topological superfluidity/superconductivity in particular. It will drive the innovation of new instrumentation at the new frontier combining ultra-low temperatures and nanoscience, and new experimental techniques of broad applicability.

This project will be undertaken in the London Low Temperature Laboratory, at Royal Holloway. We are part of the European Microkelvin Platform, which is a European Advanced Infrastructure supported by Horizon 2020.

The project “Topological mesoscopic superfluidity of 3He” is supported by EPSRC EP/R04533/1. It benefits from close international collaboration with researchers at Cornell University, NIST, PTB (Berlin), Northwestern University, Montana State Univeristy, University of Oxford, Kyoto University, University of Jyvaskyla, Oxford Instruments, York Instruments.