title: Drag effect and topological complexes in strongly interacting two-component lattice superfluids.
abstract: The mutual drag in strongly interacting two-component superfluids in optical lattices is discussed. Two competing drag mechanisms are the vacancy-assisted motion and proximity to a quasimolecular state. In a case of strong drag, the lowest energy topological excitation (vortex or persistent current) can consist of several circulation quanta. In the SQUID-type geometry, the circulation can become fractional. We present both the mean field and Monte Carlo results. The drag effects in optical lattices are drastically different from the Galilean-invariant Andreev-Bashkin effect in liquid helium.
authors.affiliation: Department of Physics, CUNY-Staten Island, New York, NY 10314, USA.
authors.forename: V M
authors.initials: VM
authors.lastname: Kaurov
authors.forename: A B
authors.initials: AB
authors.lastname: Kuklov
authors.forename: A E
authors.initials: AE
authors.lastname: Meyerovich