Phase Locked Photon Echoes for Near-Perfect Retrieval Efficiency and Extended Storage Time

TL;DR

This paper introduces a phase-locked photon echo protocol that significantly enhances quantum light storage by extending storage time and improving retrieval efficiency using a spin state locking technique.

Contribution

It presents a novel phase locking method for photon echoes that extends storage time and achieves near-perfect retrieval efficiency in quantum memory.

Findings

Extended storage time via spin dephasing control

Near-perfect retrieval efficiency demonstrated

Aberration correction enabled for quantum images

Abstract

Quantum storage of light in a collective ensemble of atoms plays an important role in quantum information processing. Consisting of a quantum repeater together with quantum entanglement swapping, quantum memory has been intensively studied recently. Conventional photon echoes have been limited by extremely low retrieval efficiency and short storage time confined by the optical phase decay process. Here, we report a storage time-extended near perfect photon echo protocol using a phase locking method via an auxiliary spin state, where the phase locking acts as a conditional stopper of the rephasing process resulting in extension of storage time determined by the spin dephasing process. We experimentally prove the proposed phase locked photon echo protocol in a Pr3+ doped Y2SiO5 in a quasi phase conjugate scheme, where the phase conjugate gives the important benefit of aberration corrections when dealing with quantum images.