Hybrid Quantum Repeater Chains with Atom-based Quantum Processing Units and Quantum Memory Multiplexers

TL;DR

This paper proposes a hybrid quantum repeater architecture combining atom-based quantum processing, quantum memories, and photon sources to enable high-rate, reliable long-distance entanglement distribution for quantum networks.

Contribution

It introduces a novel hybrid design integrating atom-based units and multiplexed memories, enhancing entanglement generation and distribution efficiency in quantum repeaters.

Findings

Demonstrates improved end-to-end secret key rates via numerical simulations.

Shows robustness of the design against photon-loss channels.

Highlights the potential for scalable quantum network deployment.

Abstract

Quantum repeaters enable the generation of reliable entanglement across long distances despite the underlying channel noise. Nevertheless, realizing quantum repeaters poses a difficult engineering challenge due to various device constraints and design tradeoffs. Herein, we propose and analyze an efficient hybrid quantum repeater design that integrates atom-based quantum processing units, spontaneous parametric down-conversion photon sources, and atomic frequency comb quantum memories. Our design leverages the strong spectro-temporal multiplexing capability of the quantum memory to enable high-rate elementary-link entanglement generation between repeater nodes. Transferring the photonic entanglement into matter-qubit entanglement, together with deterministic quantum operations, further enables reliable long-distance entanglement distribution. We analyze photon-loss channels in the hybrid architecture and propose suitable error-suppression strategies that are natively incorporated into our repeater protocol. Using numerical simulations, we demonstrate the advantages of our hybrid design for end-to-end secret key rates in a linear repeater-chain model. With continued advances in relevant hardware technologies, we envision that the proposed hybrid design is well-suited for large-scale quantum networks.