Single-photon-level quantum memory at room temperature

TL;DR

This paper demonstrates a controllable, broadband, and efficient quantum memory at room temperature using warm atomic cesium vapour, capable of storing single-photon-level signals with low noise, advancing scalable quantum information processing.

Contribution

It introduces a practical room-temperature quantum memory using warm atomic vapour, overcoming noise issues present in previous warm memories and avoiding complex cold-atom setups.

Findings

Successful storage and retrieval of weak coherent pulses at the single-photon level.

Low noise floor enabling operation in the quantum regime at room temperature.

Broadband and controllable memory performance.

Abstract

Quantum memories capable of storing single photons are essential building blocks for quantum information processing, enabling the storage and transfer of quantum information over long distances. Devices operating at room temperature can be deployed on a large scale and integrated into existing photonic networks, but so far warm quantum memories have been susceptible to noise at the single photon level. This problem is circumvented in cold atomic ensembles, but these are bulky and technically complex. Here we demonstrate controllable, broadband and efficient storage and retrieval of weak coherent light pulses at the single-photon level in warm atomic caesium vapour using the far off-resonant Raman memory scheme. The unconditional noise floor is found to be low enough to operate the memory in the quantum regime at room temperature.