Storage and retrieval of vector beams of light in a multiple-degree-of-freedom quantum memory

TL;DR

This paper demonstrates the experimental storage and retrieval of complex vector beams with structured polarization and phase in a quantum memory, preserving their properties at the single-photon level for potential quantum information applications.

Contribution

It introduces a method to store and retrieve vector vortex beams with multiple degrees of freedom in a quantum memory, preserving their structure after retrieval.

Findings

Successful storage of vector vortex modes in a quantum memory.

Preservation of phase and polarization singularities after retrieval.

Potential applications in quantum networks and classical data processing.

Abstract

The full structuration of light in the transverse plane, including intensity, phase and polarization, holds the promise of unprecedented capabilities for applications in classical optics as well as in quantum optics and information sciences. Harnessing special topologies can lead to enhanced focusing, data multiplexing or advanced sensing and metrology. Here we experimentally demonstrate the storage of such spatio-polarization-patterned beams into an optical memory. A set of vectorial vortex modes is generated via liquid crystal cell with topological charge in the optic axis distribution, and preservation of the phase and polarization singularities is demonstrated after retrieval, at the single-photon level. The realized multiple-degree-of-freedom memory can find applications in classical data processing but also in quantum network scenarios where structured states have been shown to provide promising attributes, such as rotational invariance.