arXiv:cond-mat/0205069 · Physical Review Letters

Counterflow Superfluidity of Two-Species Ultracold Atoms in a Commensurate Optical Lattice

Anatoly B. Kuklov, Boris V. Svistunov

Published Mar 12, 2003• 494 citations

Abstract

In the Mott-insulator regime, two species of ultracold atoms in an optical lattice can exhibit the low-energy counterflow motion. We construct effective Hamiltonians for the three classes of the two-species (fermion-fermion, boson-boson, and boson-fermion-type) insulators and reveal the conditions when the resulting ground state supports super-counter-fluidity (SCF), with the alternative being phase segregation. We emphasize a crucial role of breaking the isotopic symmetry between the species for realizing the SCF phase.

DOI: 10.1103/physrevlett.90.100401

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