Capacity-time Trade-off in Highly Reliable Quantum Memory

Abstract

Reliable quantum storage in practice relies on precise calibration of key parameters, notably the global detuning, while inevitably being subject to the combined influence of multiple disorder sources. In this work, a comprehensive model for an Electromagnetically induced transparency (EIT) protocol is considered, in which coupling disorder and detuning disorder are incorporated simultaneously. After quantitatively analyzing the control dynamics, a highly precise phase-detuning relation to improve calibration accuracy is obtained. Building on this result, a Berry-phase-based control strategy is proposed to mitigate the degradation caused by the global detuning. We further reveal that there exists a joint effect simultaneously induced by different disorder sources, which can substantially reshape the decoherence. Finally, an effective notion of storage capacity is introduced and a general time-capacity relation is obtained, providing guidance for subsequent experimental optimization and device design.