Entanglement distribution with wavevector-multiplexed quantum memory

TL;DR

This paper proposes a wavevector-multiplexed atomic quantum memory for quantum repeaters, significantly enhancing long-distance entanglement distribution rates and outperforming existing solutions with current quantum memory technology.

Contribution

Introduction of a wavevector-multiplexed quantum memory platform that enables quasi-deterministic entanglement over long distances, surpassing existing repeater and multiplexing methods.

Findings

Achieves high entanglement generation rates over extended distances.

Mitigates optical loss issues with current quantum memory devices.

Outperforms repeaterless and temporal multiplexing protocols.

Abstract

Feasible distribution of quantum entanglement over long distances remains a fundamental step towards quantum secure communication and quantum network implementations. Quantum repeater nodes based on quantum memories promise to overcome exponential signal decay inherent to optical implementations of quantum communication. While performance of current quantum memories hinders their practical application, multimode solutions with multiplexing can offer tremendous increase in entanglement distribution rates. We propose to use a wavevector-multiplexed atomic quantum memory (WV-MUX-QM) as a fundamental block of a multiplexed quantum repeater architecture. We show the WV-MUX-QM platform to provide quasi-deterministic entanglement generation over extended distances, mitigating the fundamental issue of optical loss even with currently available quantum memory devices, and exceeding performance of repeaterless solutions as well as other repeater-based protocols such as temporal multiplexing. We establish the entangled-bit (ebit) rate per number of employed nodes as a practical figure of merit reflecting the cost-efficiency of larger inter-node distances.