Holographic storage of multiple coherence gratings in a Bose-Einstein condensate

TL;DR

This paper demonstrates high-efficiency, long-duration storage and retrieval of multiple coherence gratings in a Bose-Einstein condensate using superradiant Raman scattering, advancing quantum memory technology.

Contribution

It introduces a method for holographic storage of multiple coherence gratings in a BEC with high efficiency and long storage times, enabling selective retrieval of stored quantum information.

Findings

Achieved >70% conversion efficiency.

Demonstrated storage time >120 microseconds.

Enabled selective retrieval of multiple gratings.

Abstract

We demonstrate superradiant conversion between a two-mode collective atomic state and a single-mode light field in an elongated cloud of Bose-condensed atoms. Two off-resonant write beams induce superradiant Raman scattering, producing two independent coherence gratings with a different wave vector in the cloud. By applying phase-matched read beams after a controllable delay, the gratings can be selectively converted into the light field also in a superradiant way. Due to the large cooperativity parameter and the small velocity width of the condensate, a high conversion efficiency of $> 70$ % and a long storage time of $> 120$ $\mu$s were achieved.