Hybrid quantum repeater with encoding

TL;DR

This paper introduces an encoded hybrid quantum repeater scheme utilizing error-correcting codes, analyzing its performance trade-offs and demonstrating feasible entanglement distribution rates over long distances.

Contribution

It proposes a specific implementation of an encoded hybrid quantum repeater with error correction and analyzes its rate-performance trade-offs under realistic conditions.

Findings

Achieves approximately 24 Hz entanglement rate over 1280 km

Identifies a triple trade-off among code efficiency, decoherence, and gate errors

Maintains high fidelity (~0.95) with reasonable imperfections

Abstract

We present an encoded hybrid quantum repeater scheme using qubit-repetition and Calderbank-Shor-Steane codes. For the case of repetition codes, we propose an explicit implementation of the quantum error-correction protocol. Moreover, we analyze the entangled-pair distribution rate for the hybrid quantum repeater with encoding and we clearly identify a triple trade-off between the efficiency of the codes, the memory decoherence time, and the local gate errors. Finally, we show that in the presence of reasonable imperfections our system can achieve rates of roughly 24 Hz per memory for 20 km repeater spacing, a final distance of 1280 km, and a final fidelity of about 0.95.