Entanglement distribution between quantum repeater nodes with an absorptive type memory

TL;DR

This paper proposes a novel entanglement distribution scheme using a single absorptive quantum memory with temporal multimode operation, significantly enhancing distribution rates for quantum communication.

Contribution

The authors introduce a new entanglement distribution method utilizing an absorptive quantum memory with atomic frequency combs, enabling high-rate distribution with only one memory crystal.

Findings

Nearly two orders of magnitude increase in distribution rate.

Feasible with current technology for experimental implementation.

Simplifies quantum memory requirements for long-distance quantum communication.

Abstract

Quantum repeaters, which are indispensable for long-distance quantum communication, are necessary for extending the entanglement from short distance to long distance; however, high-rate entanglement distribution, even between adjacent repeater nodes, has not been realized. In a recent work by C. Jones, et al., New J. Phys. 18, 083015 (2016), the entanglement distribution rate between adjacent repeater nodes was calculated for a plurality of quantum dots, nitrogen-vacancy centers in diamond, and trapped ions adopted as quantum memories inside the repeater nodes. Considering practical use, arranging a plurality of quantum memories becomes so difficult with the state-of-the art technology. It is desirable that high-rate entanglement distribution is realized with as few memory crystals as possible. Here we propose new entanglement distribution scheme with one quantum memory based on the atomic frequency comb which enables temporal multimode operation with one crystal. The adopted absorptive type quantum memory degrades the difficulty of multimode operation compared with previously investigated quantum memories directly generating spin-photon entanglement. It is shown that the present scheme improves the distribution rate by nearly two orders of magnitude compared with the result in C. Jones, et al., New J. Phys. 18, 083015 (2016) and the experimental implementation is close by utilizing state-of-the-art technology.