Higher first Chern numbers in one dimensional Bose-Fermi mixtures

Kristian Knakkergaard Nielsen; Zhigang Wu; Georg M. Bruun

doi:10.1088/1367-2630/aaaa51

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arXiv · 1710.08715

Higher first Chern numbers in one dimensional Bose-Fermi mixtures

Kristian Knakkergaard Nielsen·Zhigang Wu·Georg M. Bruun

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Abstract

We propose to use a one-dimensional system consisting of identical fermions in a periodically driven lattice immersed in a Bose gas, to realise topological superfluid phases with Chern numbers larger than 1. The bosons mediate an attractive induced interaction between the fermions, and we derive a simple formula to analyse the topological properties of the resulting pairing. When the coherence length of the bosons is large compared to the lattice spacing and there is a significant next-nearest neighbour hopping for the fermions, the system can realise a superfluid with Chern number +/- 2. We show that this phase is stable in a large region of the phase diagram as a function of the filling fraction of the fermions and the coherence length of the bosons. Cold atomic gases offer the possibility to realise the proposed system using well-known experimental techniques.

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Kristian Knakkergaard Nielsen, Zhigang Wu, Georg M. Bruun. 2018-02-15. Higher first Chern numbers in one dimensional Bose-Fermi mixtures. https://doi.org/10.1088/1367-2630%2Faaaa51

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