Superfluid-insulator transitions of the Fermi gas with near-unitary interactions in a periodic potential

Eun Gook Moon; Predrag Nikolic; Subir Sachdev

doi:10.1103/physrevlett.99.230403

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arXiv · 0707.2383

Superfluid-insulator transitions of the Fermi gas with near-unitary interactions in a periodic potential

Eun Gook Moon·Predrag Nikolic·Subir Sachdev

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Abstract

We consider spin-1/2 fermions of mass m with interactions near the unitary limit. In an applied periodic potential of amplitude V and period a, and with a density of an even integer number of fermions per unit cell, there is a second-order quantum phase transition between superfluid and insulating ground states at a critical V=Vc. We compute the universal ratio Vc m a^2 / h^2 at N=infinity in a model with Sp(2N) spin symmetry. The insulator interpolates between a band insulator of fermions and a Mott insulator of fermion pairs. We discuss implications for recent experiments.

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Eun Gook Moon, Predrag Nikolic, Subir Sachdev. 2007-08-20. Superfluid-insulator transitions of the Fermi gas with near-unitary interactions in a periodic potential. https://doi.org/10.1103/physrevlett.99.230403

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