Fiber-coupled broadband quantum memory for polarization-encoded photonic qubits

TL;DR

This paper presents a fiber-coupled quantum memory platform capable of high-fidelity storage of broadband polarization qubits, with efficiency scaling and lifetime trade-offs suitable for quantum networking.

Contribution

It introduces a novel fiber-coupled loop-and-switch quantum memory with scalable efficiency and demonstrates high-fidelity storage of broadband polarization qubits.

Findings

Pass-through efficiency of ~54%

Efficiency scales as ~0.5^(N+1) with storage cycles

High-fidelity storage of broadband polarization qubits

Abstract

Various near-term quantum networking applications will benefit from low-loss, fiber-coupled photonic quantum memory devices with high efficiencies. We demonstrate a fiber-coupled loop-and-switch quantum memory platform with a pass-through efficiency of ~54% and an overall storage efficiency that scales as ~0.5^(N+1) where N is the number of storage cycles. We highlight the trade-off between memory lifetime and qubit accessibility in this platform by using two different storage cycle times of ~40 nanoseconds and ~0.5 microseconds, and demonstrate high-fidelity storage and retrieval of ultra-broadband single-photon polarization qubits in both cases.