Storage and analysis of light-matter entanglement in a fibre-integrated system

TL;DR

This paper demonstrates a fiber-integrated quantum memory entangled with a photon at telecom wavelength, achieving significant improvements in storage time and efficiency, advancing quantum network development.

Contribution

It introduces a fiber-integrated quantum memory based on a laser-written waveguide in a rare-earth doped solid, enabling stable all-fiber entanglement storage.

Findings

Achieved orders of magnitude increase in storage time.

Enhanced efficiency of light-matter entanglement storage.

Demonstrated fiber-based analysis of entanglement.

Abstract

The deployment of a fully-fledged quantum internet poses the challenge of finding adequate building-blocks for entanglement distribution between remote quantum nodes. An ideal system would combine propagation in optical fibres with quantum memories for light, leveraging on the existing communication network while featuring the scalability required to extend to network sizes. Here we demonstrate a fiber-integrated quantum memory entangled with a photon at telecommunication wavelength. The storage device is based on a fiber-pigtailed laser written waveguide in a rare-earth doped solid and allows an all-fiber stable adressing of the memory. The analysis of the entanglement is performed using fibre-based interferometers. Our results feature orders of magnitude advances in terms of storage time and efficiency for integrated storage of light-matter entanglement, and constitute a significant step forward towards quantum networks using integrated devices.