Vortex coupler for atomic Bose-Einstein condensates

TL;DR

This paper proposes a method to generate vortex states in Bose-Einstein condensates using Raman transitions with Laguerre-Gaussian laser beams, enabling controlled angular momentum transfer.

Contribution

It introduces a novel vortex coupler technique employing copropagating laser beams with specific polarization and frequency configurations for BECs.

Findings

The proposed method effectively transfers angular momentum to create vortex states.

Theoretical analysis shows coherent coupling between ground and vortex states.

Detection strategies for vortex states are discussed.

Abstract

A coherent coupler is proposed to spin a Bose-Einstein condensate composed of ultracold alkali atoms into a vortex state (VS). The proposal is based on a Raman transition induced by two copropagating $\sigma^+$ and $\sigma^-$ polarized Laguerre-Gaussian laser beams with different frequencies. We show that the transfer of angular momentum of photons to the condensed atoms through a Raman transition leads to a coherent coupling of the ground-state condensate to a rotating condensate in a VS. The detection of such a VS is discussed.