Certifying quantum memories with coherence

TL;DR

This paper introduces a coherence-based quality measure for quantum memories, providing criteria for evaluation, detailed characterization for qubits, and practical estimation methods from limited data, enhancing quantum information processing reliability.

Contribution

It proposes a novel coherence-based measure for quantum memory quality, fulfilling specific criteria, and offers a practical approach for experimental estimation and potential generalization to other quantum components.

Findings

The measure satisfies key quality criteria for quantum memories.

It is explicitly characterized for qubit systems.

The measure can be efficiently estimated from sparse experimental data.

Abstract

Quantum memories are an important building block for quantum information processing. Ideally, these memories preserve the quantum properties of the input. We present general criteria for measures to evaluate the quality of quantum memories. Then, we introduce a quality measure based on coherence satisfying these criteria, which we characterize in detail for the qubit case. The measure can be estimated from sparse experimental data and may be generalized to characterize other building blocks, such as quantum gates and teleportation schemes.