Broadband quantum memory in a cavity via zero spectral dispersion

TL;DR

This paper proposes a broadband optical quantum memory design using dispersion compensation via Raman processes in atomic ensembles, enabling high efficiency and large mode capacity for telecom quantum networks.

Contribution

It introduces a novel dispersion compensation technique for quantum memory using Raman processes, enhancing bandwidth and multiplexing capabilities.

Findings

Dispersion compensation extends impedance matching over a full cavity linewidth.

Memory could achieve over 90% efficiency with a one-second spin coherence.

Supports over 10^6 modes for temporal multiplexing.

Abstract

We seek to design experimentally feasible broadband, temporally multiplexed optical quantum memory with near-term applications to telecom bands. Specifically, we devise dispersion compensation for an impedance-matched narrow-band quantum memory by exploiting Raman processes over two three-level atomic subensembles, one for memory and the other for dispersion compensation. Dispersion compensation provides impedance matching over more than a full cavity linewidth. Combined with one second spin-coherence lifetime the memory could be capable of power efficiency exceeding 90% leading to 106 modes for temporal multiplexing. Our design could lead to significant multiplexing enhancement for quantum repeaters to be used for telecom quantum networks.