Driving quantized vortices with quantum vacuum fluctuations
Instituto de Fisica, UFRJ - CP 68528, Rio de Janeiro, RJ, 21941-972, Brazil
2 Theoretical Division, MS B213, Los Alamos National Laboratory - Los Alamos, NM 87545, USA
3 Laboratoire Kastler Brossel, case 74, CNRS, ENS, UPMC, Campus Jussieu - F-75252 Paris Cedex 05, France, EU
Accepted: 5 November 2010
We propose to use a rotating corrugated material plate in order to stir, through the Casimir-Polder interaction, quantized vortices in an harmonically trapped Bose-Einstein condensate. The emergence of such vortices within the condensate cannot be explained with a computation of the Casimir-Polder potential based on the pairwise summation approach or on the proximity force approximation. It thus appears as a genuine signature of non-trivial geometry effects on the electromagnetic vacuum fluctuations, which fully exploits the superfluid nature of the sample. In order to discuss quantitatively the generation of Casimir-driven vortices, we derive an exact non-perturbative theory of the Casimir-Polder potential felt by the atoms in front of the grating. Our numerical results for a Rb condensate close to a Si grating show that the resulting quantum vacuum torque is strong enough to provide a contactless transfer of angular momentum to the condensate and generate quantized vortices under realistic experimental conditions at separation distances around 3 μm.
PACS: 03.75.Lm – Tunneling, Josephson effect, Bose-Einstein condensates in periodic potentials, solitons, vortices, and topological excitations / 12.20.Ds – Specific calculations / 34.35.+a – Interactions of atoms and molecules with surfaces
© EPLA, 2010