Telecommunication-wavelength solid-state memory at the single photon level

TL;DR

This paper demonstrates the first solid-state quantum memory at telecommunication wavelengths capable of storing and retrieving single-photon level light pulses for up to 600 ns using an Erbium-doped crystal.

Contribution

It introduces a novel implementation of photon echo memory with controlled reversible inhomogeneous broadening at the single photon level in a solid-state system.

Findings

Successful storage and retrieval of single-photon level pulses

Storage duration up to 600 nanoseconds

Implementation of controlled reversible inhomogeneous broadening using the Stark effect

Abstract

We demonstrate experimentally the storage and retrieval of weak coherent light fields at telecommunication wavelengths in a solid. Light pulses at the single photon level are stored for a time up to 600 ns in an Erbium-doped Y$_2$SiO$_5$ crystal at 2.6 K and retrieved on demand. The memory is based on photon echoes with controlled reversible inhomogeneous broadening, which is realized here for the first time at the single photon level. This is implemented with an external field gradient using the linear Stark effect. This experiment demonstrates the feasibility of a solid state quantum memory for single photons at telecommunication wavelengths, which would represent an important resource in quantum information science.