Driving quantized vortices with quantum vacuum fluctuations

¹ 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

Received: 15 September 2010
Accepted: 5 November 2010

Abstract

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.