Projects per year
Abstract
Superfluid ^{3}He, with unconventional spintriplet pwave pairing, provides a model system for topological superconductors, which have attracted significant interest through potential applications in topologically protected quantum computing. In topological insulators and quantum Hall systems, the surface/edge states, arising from bulksurface correspondence and the momentum space topology of the band structure, are robust. Here we demonstrate that in topological superfluids and superconductors the surface Andreev bound states, which depend on the momentum space topology of the emergent order parameter, are fragile with respect to the details of surface scattering. We confine superfluid ^{3}He within a cavity of height D comparable to the Cooper pair diameter ξ_{0}. We precisely determine the superfluid transition temperature T_{c} and the suppression of the superfluid energy gap, for different scattering conditions tuned in situ, and compare to the predictions of quasiclassical theory. We discover that surface magnetic scattering leads to unexpectedly large suppression of T_{c}, corresponding to an increased density of low energy bound states.
Original language  English 

Article number  1574 
Journal  Nature Communications 
Volume  12 
DOIs  
Publication status  Published  10 Mar 2021 
Projects
 3 Finished

EMP: European Microkelvin Platform
Saunders, J. (PI), Casey, A. (CoI), Astafiev, O. (CoI), Nyeki, J. (CoI) & Levitin, L. (CoI)
1/01/19 → 31/12/23
Project: Research

Topological mesoscopic superfluidity of helium 3
Saunders, J. (PI), Casey, A. (CoI), Eschrig, M. (CoI), Cowan, B. (CoI), Rojas, X. (CoI) & Heikkinen, P. (Researcher)
Eng & Phys Sci Res Council EPSRC
1/07/18 → 31/12/21
Project: Research

Topological superfluids under engineered nanofluidic confinement: new order parameters and exotic excitations
Saunders, J. (PI), Casey, A. (CoI), Cowan, B. (CoI), Eschrig, M. (CoI), Yager, B. (CoI), Levitin, L. (CoI) & Sumner, L. (CoI)
Eng & Phys Sci Res Council EPSRC
1/10/12 → 30/09/16
Project: Research