Critical Rotational Speeds in the Gross-Pitaevskii Theory on a Disc with Dirichlet Boundary Conditions
Michele Correggi, Florian Pinsker, Nicolas Rougerie, Jakob Yngvason, M. Correggi A, F. Pinsker B, Nicolas Rougerie, Jakob Yngvason
Abstract
We study the two-dimensional Gross-Pitaevskii theory of a rotating Bose gas in a disc-shaped trap with Dirichlet boundary conditions, generalizing and extending previous results that were obtained under Neumann boundary conditions. The focus is on the energy asymptotics, vorticity and qualitative properties of the minimizers in the parameter range | log ε | ≪ Ω � ε −2 | log ε | −1 where Ω is the rotational velocity and the coupling parameter is written as ε −2 with ε ≪ 1. Three critical speeds can be identified. At Ω = Ωc1 ∼ | log ε | vortices start to appear and for | log ε | ≪ Ω < Ωc2 ∼ ε −1 the vorticity is uniformly distributed over the disc. For Ω ≥ Ωc2 the centrifugal forces create a hole around the center with strongly depleted density. For Ω ≪ ε −2 | log ε | −1 vorticity is still uniformly distributed in an annulus containing the bulk of the density, but at Ω = Ωc3 ∼ ε −2 | log ε | −1 there is a transition to a giant vortex state where the vorticity disappears from the bulk. The energy is