Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Counterflow Superfluidity of Two-Species Ultracold Atoms in a
  Commensurate Optical Lattice   If two species of ultracold atoms are loaded in a sufficiently tight optical
lattice at a commensurate total filling factor, the net number-of-atoms
transport is suppressed by the Mott-Hubbard localization. Nonetheless, the
counterflow low-frequency dynamics of the two components may survive. We
consider corresponding effective Hamiltonians for the three classes of the
two-species insulators-- fermion-fermion, boson-boson, and boson-fermion type--
and reveal the conditions when the resulting groundstate supports
super-counter-fluidity (SCF) of the two components. Alternative groundstates
are found to be phase-segregated states. We emphasize a crucial role of
breaking the isotopic symmetry between the species for realizing the SCF phase.

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The categories of this paper are: cs
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The categories of this paper are: atom-ph
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The categories of this paper are: gr-qc
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The categories of this paper are: ao-sci
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The categories of this paper are: supr-con
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The categories of this paper are: cmp-lg
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The categories of this paper are: q-alg
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The categories of this paper are: econ
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The categories of this paper are: eess
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The categories of this paper are: hep-ph
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The categories of this paper are: adap-org
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The categories of this paper are: math
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The categories of this paper are: q-fin
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The categories of this paper are: hep-lat
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The categories of this paper are: bayes-an
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The categories of this paper are: hep-th