Arbitrary Coherent Superpositions of Quantized Vortices in Bose-Einstein Condensates from Orbital Angular Momentum Beams of Light

TL;DR

This paper presents a method to transfer superpositions of orbital angular momentum states of light to Bose-Einstein condensates, enabling the creation of complex vortex states for quantum information and fundamental studies.

Contribution

It introduces a time-reversal-symmetric scheme for transferring OAM superpositions to BECs using a Raman process similar to STIRAP, and discusses trap configurations for large vortices.

Findings

Successful transfer of OAM superpositions to BECs demonstrated

Proposed techniques enable creation of large charge vortices

Potential applications in quantum information processing and quantum memory

Abstract

We recently proposed a scheme for the creation of coherent superpositions of vortex states in Bose-Einstein condensates (BEC) using orbital angular momentum (OAM) states of light [Phys. Rev. Lett. 95, 173601 (2005)]. Here we discuss further technical details of the proposal, provide alternative, time-reversal-symmetric scheme for transfer of a superposition of OAM states of light to the BEC via a procedure analogous to the traditional STimulated Raman Adiabatic Passage (STIRAP) technique, and discuss an alternative trap configuration conducive for sustaining large charge vortices. Superpositions of OAM states of light, created using experimental techniques, can be transfered to an initially nonrotating BEC via a specially devised Raman coupling scheme. The techniques proposed here open up avenues to study coherent interaction of OAM states of light with matter. The study could also be employed for performing various quantum information processing tasks with OAM states of light--including a memory for a quantum state of the initial superposition.