Backward propagating quantum repeater protocol with multiple quantum memories

TL;DR

This paper introduces a backward propagating quantum repeater protocol that multiplexes quantum memories in the time domain, enabling faster and more feasible long-distance quantum communication without full connectivity among memories.

Contribution

The proposed protocol simplifies quantum repeater implementation by eliminating the need for full connectivity, using backward photon emission and absorption with time-multiplexed quantum memories.

Findings

Protocol speeds up quantum communication channels.

Applicable to various physical systems beyond NV centers.

Facilitates high-speed, high-fidelity quantum networks.

Abstract

Quantum repeaters with multiple quantum memories provide high throughput, low latency, and high fidelity quantum state (qubit) transfer over long distances. However, conventional quantum repeater protocols require full connections among the multiple quantum memories in a repeater node, which is technically challenging. Here, we propose a quantum repeater protocol based on backward propagating photon emission and absorption, where the quantum memories are multiplexed in the time-domain to speed up a single transmission channel without requiring full connectivity, drastically facilitating physical implementation. Although the protocol is described with nitrogen-vacancy (NV) centers in diamond, it is applicable to various physical systems and opens up the possibility of high-speed high-fidelity quantum networks for distributed quantum computation and quantum Internet.