Harnessing optical vortices to control current flow via quantized torque in coherently prepared multilevel atoms

Abstract

This study delves into the interaction between coherently prepared trapped atoms and optical vortices, focusing on the intriguing phenomenon of light-induced torque enhancement and the resultant persistent current flow. Beginning with a three-level atom ensemble in the Λ configuration, we initiate a coherent superposition of lower levels to establish a coherent population trapping medium. The atoms interact with a pair of optical vortices, producing a quantized torque on each trapped atom that is directly proportional to the topological charge of the inhomogeneous coupling beams. This torque imparts a rotation to the entire ensemble, thereby generating a striking ring-shaped atomic current flow. With careful manipulation of the initial internal state of the atoms and the strength of the vortex pair, we can control the magnitude of the torque. Extending the model to include more complex level schemes with additional laser beams offers even greater potential for enhancing light-induced torque and refining our control over the current flow.