Towards the device-independent certification of a quantum memory

TL;DR

This paper introduces a robust, device-independent method for certifying quantum memories, demonstrating its effectiveness by certifying a high fidelity in a recent experiment, which is crucial for future quantum communication networks.

Contribution

The paper develops a novel self-testing approach for quantum memories that does not require prior device characterization, applicable to any qubit identity channel.

Findings

Certified a fidelity of 0.87 in a solid-state quantum memory experiment

Developed a robust self-testing method for quantum memories

Applicable to characterizing any device implementing a qubit identity channel

Abstract

Quantum memories represent one of the main ingredients of future quantum communication networks. Their certification is therefore a key challenge. Here we develop efficient certification methods for quantum memories. Considering a device-independent approach, where no a priori characterisation of sources or measurement devices is required, we develop a robust self-testing method for quantum memories. We then illustrate the practical relevance of our technique in a relaxed scenario by certifying a fidelity of 0.87 in a recent solid-state ensemble quantum memory experiment. More generally, our methods apply for the characterisation of any device implementing a qubit identity quantum channel.