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arXiv · 0803.1498

Evolution from BCS to BKT superfluidity in one-dimensional optical lattices

M. Iskin·C. A. R. S á de Melo
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Abstract

We analyze the finite temperature phase diagram of fermion mixtures in one-dimensional optical lattices as a function of interaction strength. At low temperatures, the system evolves from an anisotropic three-dimensional Bardeen-Cooper-Schrieffer (BCS) superfluid to an effectively two-dimensional Berezinskii-Kosterlitz-Thouless (BKT) superfluid as the interaction strength increases. We calculate the critical temperature as a function of interaction strength, and identify the region where the dimensional crossover occurs for a specified optical lattice potential. Finally, we show that the dominant vortex excitations near the critical temperature evolve from multiplane elliptical vortex loops in the three-dimensional regime to planar vortex-antivortex pairs in the two-dimensional regime, and we propose a detection scheme for these excitations.

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M. Iskin, C. A. R. S á de Melo. 2008-03-10. Evolution from BCS to BKT superfluidity in one-dimensional optical lattices. https://doi.org/10.1103/physrevlett.103.165301

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