title: Anomalous hydrodynamics and normal fluids in rapidly rotating Bose-Einstein condensates.
abstract: In rapidly rotating condensed Bose systems we show that there is a regime of anomalous hydrodynamics which coincides with the mean field quantum Hall regime. A consequence is the absence of a normal fluid in any conventional sense. However, even the superfluid hydrodynamics is not described by conventional Bernoulli and continuity equations. We show that there are constraints which connect spatial variations of density and phase and that the vortex positions are not the simplest description of the dynamics. We demonstrate, inter alia, a simple relation between vortices and surface waves. We show that the surface waves can emulate a "normal fluid," allowing dissipation by energy and angular momentum absorbtion from vortex motion in the trap. The time scale is sensitive to the initial configuration, which can lead to long-lived vortex patches--perhaps related to those observed at JILA.
authors.affiliation: School of Physics and Astronomy, University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom.
authors.forename: A
authors.initials: A
authors.lastname: Bourne
authors.forename: N K
authors.initials: NK
authors.lastname: Wilkin
authors.forename: J M F
authors.initials: JM
authors.lastname: Gunn