Driving quantized vortices with quantum vacuum fluctuations

TL;DR

This paper demonstrates that quantum vacuum fluctuations, manipulated via a rotating corrugated surface, can generate quantized vortices in a Bose-Einstein condensate, revealing novel geometry-dependent electromagnetic effects.

Contribution

It introduces a non-perturbative theory for Casimir-Polder interactions with complex geometries and shows how vacuum fluctuations can induce vortices in superfluids.

Findings

Quantum vacuum torque can transfer angular momentum to BECs.

Quantized vortices can be generated at micron-scale separations.

Geometry effects significantly influence electromagnetic vacuum fluctuations.

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 $3$ microns.