PhysicalReviewB-82-045110-2010.pdf (581.57 kB)
Download fileLifshitz transitions and crystallization of fully polarized dipolar fermions in an anisotropic two-dimensional lattice
journal contribution
posted on 2013-07-15, 11:17 authored by Sam T. Carr, Jorge Quintanilla, Joseph BetourasJoseph BetourasWe consider a two-dimensional model of noninteracting chains of spinless fermions weakly coupled via a small interchain hopping and a repulsive interchain interaction. The phase diagram of this model has a surprising feature: an abrupt change in the Fermi surface as the interaction is increased. We study in detail this metanematic transition and show that the well-known 2 1 2 -order Lifshitz transition is the critical end point of this first-order quantum phase transition. Furthermore, in the vicinity of the end point, the order parameter has a nonperturbative BCS-type form. We also study a competing crystallization transition in this model and derive the full phase diagram. This physics can be demonstrated experimentally in dipolar ultracold atomic or molecular gases. In the presence of a harmonic trap, it manifests itself as a sharp jump in the density profile. © 2010 The American Physical Society.
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