Seminars
Topological superfluid in a Fermi-Bose mixture with a high critical temperature
April 27th, 2017 GEORG BRUUN AARHUS UNIVERSITY

We show that a two-dimensional (2D) spin-polarised Fermi gas immersed in a 3D Bose-Einstein condensate (BEC) constitutes a very promising system to realise a topological superfluid. The fermions attract each other via an induced interaction mediated by the bosons, and the resulting pairing is analysed with retardation effects fully taken into account. This is further combined with Berezinskii-Kosterlitz-Thouless (BKT) theory to obtain reliable results for the superfluid critical temperature. We show that both the strength and the range of the induced interaction can be tuned experimentally, which can be used to make the critical temperature approach the maximum value allowed by general BKT theory. Moreover, this is achieved while keeping the Fermi-Bose interaction weak so that three-body losses are small. We furthermore show that if the fermions are confined in two layers, they can realise a so-called Z_2 topological superfluid with time-reversal symmetry.


Seminar, April 27, 2017, 15:00. Seminar Room

Hosted by Prof. Maciej Lewenstein

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