title: Vortex lattice formation in Bose-Einstein condensates.
abstract: We show that the formation of a vortex lattice in a weakly interacting Bose condensed gas can be modeled with the nonlinear Schrödinger equation for both T=0 and finite temperatures without the need for an explicit damping term. Applying a weak rotating anisotropic harmonic potential, we find numerically that the turbulent dynamics of the field produces an effective dissipation of the vortex motion and leads to the formation of a lattice. For T=0, this turbulent dynamics is triggered by a rotational dynamic instability of the condensate. For finite temperatures, noise is present at the start of the simulation and allows the formation of a vortex lattice at a lower rotation frequency, the Landau frequency. These two regimes have different vortex dynamics. We show that the multimode interpretation of the classical field is essential.
authors.affiliation: Laboratoire Kastler Brossel, Ecole Normale Supérieure, 24 rue Lhomond, 75231 Paris CEDEX 05, France.
authors.forename: Carlos
authors.initials: C
authors.lastname: Lobo
authors.forename: Alice
authors.initials: A
authors.lastname: Sinatra
authors.forename: Yvan
authors.initials: Y
authors.lastname: Castin