Cavity Optomechanical Quantum Memory for Twisted Photons Using a Ring BEC

TL;DR

This paper proposes a novel quantum memory platform using a ring Bose-Einstein condensate to store photonic orbital angular momentum states, achieving significantly longer storage times and higher bandwidth than existing methods.

Contribution

It introduces a cavity optomechanical quantum memory that stores OAM states in motional states of a BEC without changing atomic levels, enhancing storage time and bandwidth.

Findings

Storage time is three orders of magnitude longer than current methods.

The system offers significantly increased bandwidth for reading and writing.

Potential for wavelength conversion and nondestructive readout via cavity optomechanics.

Abstract

We theoretically propose a photonic orbital angular momentum (OAM) quantum memory platform based on an atomic Bose-Einstein condensate confined in a ring trap and placed inside a Fabry-Perot cavity driven by Laguerre-Gaussian beams. In contrast to electromagnetically induced transparency-based protocols, our memory does not require change of internal atomic levels. The optical states are instead stored in the large Hilbert space of topologically protected and long-lived motional states (persistent currents) of the condensate, yielding a storage time three orders of magnitude better than presently available. Further, the use of a cavity provides orders of magnitude more resonances, and hence bandwidth, for reading and writing than internal atomic transitions. Finally, the analogy to cavity optomechanics suggests a natural path to wavelength conversion, OAM transduction, and nondestructive readout of the memory.