Issue
EPL
Volume 80, Number 5, December 2007
Article Number 50004
Number of page(s) 6
Section General
DOI http://dx.doi.org/10.1209/0295-5075/80/50004
Published online 29 October 2007
EPL, 80 (2007) 50004
DOI: 10.1209/0295-5075/80/50004

AC-induced superfluidity

A. Eckardt and M. Holthaus

Institut für Physik, Carl von Ossietzky Universität - D-26111 Oldenburg, Germany

eckardt@theorie.physik.uni-oldenburg.de

received 4 September 2007; accepted in final form 4 October 2007; published December 2007
published online 29 October 2007

Abstract
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.

PACS
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