Cold atomic ensembles as quantum antennas for distributed networks of single-atom arrays

TL;DR

This paper proposes using cold atomic ensembles as quantum antennas to enhance atom-photon entanglement in distributed quantum networks, achieving high efficiency and rate with advantages over existing methods.

Contribution

It introduces a novel architecture employing atomic ensembles as quantum antennas, improving entanglement efficiency and rate in distributed quantum networks.

Findings

Estimated atom-photon entanglement efficiency of 54.8%.

Achieved a remote atom-atom entanglement probability of 6%.

Generated entanglement at a rate of 16.6 kHz.

Abstract

Single neutral atoms in optical tweezer arrays offer a promising platform for high-fidelity quantum computing at local nodes. Nonetheless, creating entanglement between remote nodes in a distributed quantum network remains challenging due to inherently weak atom-light coupling. Here, we design a distributed quantum network architecture in which cold atomic ensembles with strong atom-light interactions act as quantum antennas, interfacing single-atom qubits with flying photons to enable high-efficiency atom-photon entanglement generation -- analogous to the role of antennas in classical communication. Using realistic experimental parameters, we estimate an efficiency of $\eta \simeq 0.548$ for generating atom-photon entanglement, a probability of $P_{E} \simeq 6 \%$ for generating atom-atom entanglement, and a remote entanglement generation rate of $16.6 $ kHz. This performance not only surpasses that of state-of-the-art cavity-based or high-numerical-aperture-lens-based architectures but also offers notable advantages in simplicity, tunability, and experimental accessibility. Our scheme also integrates a long-lived quantum memory, providing a storage advantage for quantum repeater design. By leveraging the complementary strengths of single-atom qubits for local operations and cold atomic ensembles for networking, this approach paves the way for scalable distributed quantum computing and sensing.