Drag effect and topological complexes in strongly interacting two-component lattice superfluids.
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.
Kaurov
V M
VM
Department of Physics, CUNY-Staten Island, New York, NY 10314, USA.
Kuklov
A B
AB
Meyerovich
A E
AE