High capacity spatial multimode quantum memories based on atomic ensembles

TL;DR

This paper demonstrates that atomic ensemble-based quantum memories can efficiently store multiple spatial modes, with scalability depending on physical parameters like Fresnel number and optical depth, leveraging both longitudinal and transverse mode shapes.

Contribution

It introduces a novel approach to multimode quantum memories using atomic ensembles that exploits both longitudinal and transverse mode shapes for enhanced capacity.

Findings

Quadratic scaling of efficiency with Fresnel number.

Cubic scaling of efficiency with optical depth.

Utilization of both longitudinal and transverse modes enhances storage capacity.

Abstract

We study spatial multimode quantum memories based on light storage in extended ensembles of Lambda-type atoms. We show that such quantum light-matter interfaces allow for highly efficient storage of many spatial modes. In particular, forward operating memories possess excellent scaling with the important physical parameters: quadratic scaling with the Fresnel number and even cubic with the optical depth of the atomic ensemble. Thus, the simultaneous use of both the longitudinal and transverse shape of the stored spin wave modes constitutes a valuable and so far overlooked resource for multimode quantum memories.