Progress towards efficient 4-level photon echo memories

TL;DR

This paper reports a significant advancement in quantum memory technology, achieving up to 80% efficiency in a 4-level photon echo memory using Er:YSO, with capabilities for multi-mode storage and non-classical correlations, paving the way for quantum networking.

Contribution

Demonstrated a high-efficiency 4-level photon echo quantum memory with multi-mode storage and non-classical correlations, and outlined pathways for further improvements.

Findings

Achieved up to 80% recall efficiency.

Stored 70 temporal modes with 25 us storage time.

Established non-classical correlations between ASE and RASE fields.

Abstract

Quantum memories could benefit many devices in quantum information processing. For a quantum to be useful in real-world applications, the quantum memory must have a high recall efficiency. Here we demonstrate an efficient (up to 80%) spin-storage quantum memory in Er:YSO, using the 4-level rephased amplified spontaneous emission protocol. We show non-classical correlations between the ASE and RASE fields produced by the quantum memory. Also, we demonstrate the storage of 70 temporal modes, with a write time of 150 us, and a storage time of 25 us. Finally, a clear pathway is presented to improve the efficiency, storage time, and mode capacity. Such a device would have applications in quantum networking and measurement-based quantum computing.