Rate analysis for a hybrid quantum repeater

TL;DR

This paper provides an analytical rate analysis for a hybrid quantum repeater protocol using atomic qubits and optical communication, highlighting the effects of purification and multiplexing on entanglement distribution over long distances.

Contribution

It derives an exact formula for entanglement generation rates in hybrid quantum repeaters and compares purification and multiplexing strategies under realistic conditions.

Findings

Hybrid system can generate near-maximally entangled pairs over 1280 km.

Purification remains advantageous over multiplexing at low local losses.

Achieves entanglement rates of about 100 Hz over long distances.

Abstract

We present a detailed rate analysis for a hybrid quantum repeater assuming perfect memories and using optimal probabilistic entanglement generation and deterministic swapping routines. The hybrid quantum repeater protocol is based on atomic qubit-entanglement distribution through optical coherent-state communication. An exact, analytical formula for the rates of entanglement generation in quantum repeaters is derived, including a study on the impacts of entanglement purification and multiplexing strategies. More specifically, we consider scenarios with as little purification as possible and we show that for sufficiently low local losses, such purifications are still more powerful than multiplexing. In a possible experimental scenario, our hybrid system can create near-maximally entangled (F = 0.98) pairs over a distance of 1280 km at rates of the order of 100 Hz.