AC-induced superfluidityA. Eckardt and M. Holthaus
Institut für Physik, Carl von Ossietzky Universität - D-26111 Oldenburg, Germany
received 4 September 2007; accepted in final form 4 October 2007; published December 2007
published online 29 October 2007
We argue that a system of ultracold bosonic atoms in a tilted optical lattice can become superfluid in response to resonant AC forcing. Among others, this allows one to prepare a Bose-Einstein condensate in a state associated with a negative effective mass. Our reasoning is backed by both exact numerical simulations for systems consisting of few particles, and by a theoretical approach based on Floquet-Fock states.
03.75.Lm - Tunneling, Josephson effect, Bose-Einstein condensates in periodic potentials, solitons, vortices, and topological excitations.
03.75.Kk - Dynamic properties of condensates; collective and hydrodynamic excitations, superfluid flow.
© Europhysics Letters Association 2007