Time Reversal Invariant BCS-BEC Topological Superfluids

by Tommy on 30/05/2017

Here it comes, one way or another the nutshell will be cracked.


Time-reversal invariant topological superfluids in Bose-Fermi mixtures, Jonatan Melkær Midtgaard, Zhigang Wu and G. M. Bruun (29 May 2017)

A mixed dimensional system of fermions in two layers immersed in a Bose-Einstein condensate (BEC) is shown to be a promising setup to realise topological superfluids with time-reversal symmetry (TRS). The induced interaction between the fermions mediated by the BEC gives rise to a competition between p-wave pairing within each layer and s-wave pairing between the layers. When the layers are far apart, intra-layer pairing dominates and the system forms a topological superfluid either with or without TRS. With decreasing layer separation or increasing BEC coherence length, inter-layer pairing sets in. We show that this leads either to a second order transition breaking TRS where the edge modes gradually become gapped, or to a first order transition to a topologically trivial s-wave superfluid. Our results provide a realistic roadmap for experimentally realising a topological superfluid with TRS for the first time.

What usually happens though is that you end up breaking the nutcracker.


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