Practical Quantum Repeaters with Parametric Down-Conversion Sources

TL;DR

This paper demonstrates that practical quantum repeaters can be built using parametric down-conversion sources, frequency-multiplexed memories, and photon-number resolving detectors, enabling longer-distance quantum communication.

Contribution

It introduces a quantum repeater architecture utilizing simple PDC sources and multimode memories, challenging the need for deterministic entangled photon sources.

Findings

Significantly extends quantum communication distances

Shows trade-offs between components of quantum repeaters

Uses accessible, non-deterministic sources effectively

Abstract

Conventional wisdom suggests that realistic quantum repeaters will require quasi-deterministic sources of entangled photon pairs. In contrast, we here study a quantum repeater architecture that uses simple parametric down-conversion sources, as well as frequency-multiplexed multimode quantum memories and photon-number resolving detectors. We show that this approach can significantly extend quantum communication distances compared to direct transmission. This shows that important trade-offs are possible between the different components of quantum repeater architectures.