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arXiv:1304.4511 · Physical Review A

Spin-orbit coupling effects on the superfluidity of a Fermi gas in an optical lattice

Qing‐Feng Sun, Guanyu Zhu, W.-M. Liu, A.-C. Ji

Published Dec 23, 2013• 27 citations
arXivHTMLPDF

Abstract

We investigate the superfluidity of attractive Fermi gas in a square optical lattice with spin-orbit coupling (SOC). We show that the system displays a variety of new features. At half filling, SOC induces a Dirac semimetal and the system undergoes a semimetal-superfluid transition. Near half filling, we find that the superfluidity tends to be suppressed due to the emerging Dirac cones. While for small fillings, SOC can induce a BCS-BEC crossover beyond the conventional attractive Hubbard model, which is characterized by a bound state in the lattices. Moreover, we demonstrate that the superfluid density also exhibits many unusual properties in the lattices.

DOI
10.1103/physreva.88.063637

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