title: Fragmented condensate ground state of trapped weakly interacting bosons in two dimensions.
abstract: The ground state and its structure for a rotating, harmonically trapped N-boson system with a weak repulsive contact interaction are studied as the angular momentum L increases up to 3N. We show that the ground state is generally a fragmented condensate due to angular momentum conservation. In response to an (arbitrarily weak) asymmetric perturbation of the trap, however, the fragmented ground state can be transformed into a single condensate state. We manifest this intrinsic instability by calculating the conditional probability distributions, which show patterns analogous to the boson density distributions predicted by mean-field theory.
authors.affiliation: Department of Physics, Tsinghua University, Beijing 100084, China.
authors.forename: X J
authors.initials: XJ
authors.lastname: Liu
authors.forename: H
authors.initials: H
authors.lastname: Hu
authors.forename: L
authors.initials: L
authors.lastname: Chang
authors.forename: W
authors.initials: W
authors.lastname: Zhang
authors.forename: S Q
authors.initials: SQ
authors.lastname: Li
authors.forename: Y Z
authors.initials: YZ
authors.lastname: Wang