Variance-Based Sensitivity Analysis of $\Lambda$-type Quantum Memory

TL;DR

This paper analyzes how fluctuations and drift affect the efficiency of $ ext{Lambda}$-type quantum memory, providing a variance-based framework to identify sensitive parameters and improve experimental robustness.

Contribution

It introduces a variance-based sensitivity analysis framework for quantum memory, highlighting protocol-dependent sensitivities and extending applicability beyond efficiency metrics.

Findings

Memory sensitivity depends on the specific protocol used.

The framework identifies parameters most affected by fluctuations and drift.

Results inform experimental strategies for more robust quantum memory implementations.

Abstract

The storage and retrieval of photonic quantum states, quantum memory, is a key resource for a wide range of quantum applications. Here we investigate the sensitivity of $\Lambda$-type quantum memory to experimental fluctuations and drift. We use a variance-based approach, focusing on the effects of fluctuations and drift on memory efficiency. We consider shot-to-shot fluctuations of the memory parameters, and separately we consider longer timescale drift of the control field parameters. We find the parameters that a quantum memory is most sensitive to depend on the quantum memory protocol being employed, where the observed sensitivity agrees with physical interpretation of the protocols. We also present a general framework that is applicable to other figures of merit beyond memory efficiency. These results have practical ramifications for quantum memory experiments.