title: Nonequilibrium effects of anisotropic compression applied to vortex lattices in bose-einstein condensates.
abstract: We have studied the dynamics of large vortex lattices in a dilute-gas Bose-Einstein condensate. While undisturbed lattices have a regular hexagonal structure, large-amplitude quadrupolar shape oscillations of the condensate are shown to induce a wealth of nonequilibrium lattice dynamics. When exciting an m=-2 mode, we observe shifting of lattice planes, changes of lattice structure, and sheetlike structures in which individual vortices appear to have merged. Excitation of an m=+2 mode dissolves the regular lattice, leading to randomly arranged but still strictly parallel vortex lines.
authors.affiliation: JILA, National Institute of Standards and Technology and Department of Physics, University of Colorado, Boulder 80309-0440, USA.
authors.forename: P
authors.initials: P
authors.lastname: Engels
authors.forename: I
authors.initials: I
authors.lastname: Coddington
authors.forename: P C
authors.initials: PC
authors.lastname: Haljan
authors.forename: E A
authors.initials: EA
authors.lastname: Cornell