title: Delocalizing transition of Bose-Einstein condensates in optical lattices.
abstract: A Bose-Einstein condensate trapped in a two-dimensional optical lattice exhibits an abrupt transition manifested by the macroscopic wave function changing character from spatially localized to extended. Resulting from a bifurcation, this irreversible transition takes place as the interwell potential barrier is adiabatically decreased below a critical value. This is in sharp contrast to the corresponding one-dimensional case where such a bifurcation is absent and the extent of a localized mode is continuously tunable. We demonstrate how these phenomena can be experimentally explored.
authors.affiliation: Theoretical Division and Center for Nonlinear Studies, Los Alamos National Laboratory, Los Alamos, New Mexico 8754, USA.
authors.forename: G
authors.initials: G
authors.lastname: Kalosakas
authors.forename: K Ø
authors.initials: KØ
authors.lastname: Rasmussen K
authors.forename: A R
authors.initials: AR
authors.lastname: Bishop