Entanglement generation using single-photon pulse reflection in realistic networks

TL;DR

This paper presents a theoretical protocol for generating entanglement between remote stationary qubits via single-photon reflection in realistic photonic networks, accounting for practical imperfections and various physical implementations.

Contribution

It develops a comprehensive model for entanglement generation that includes finite bandwidth photons, weak coupling regimes, and node variability, applicable to diverse quantum systems.

Findings

Optimized entanglement rate and fidelity for various parameters.

Effective protocol for weak coupling and low cooperativity regimes.

Adaptability to different physical implementations like nitrogen and silicon vacancy centers.

Abstract

A general entanglement generation protocol between remote stationary qubits using single-photon reflection in a photonic network is explored theoretically. The nodes of the network consist of single qubits that are typically represented by the spin of a color center, each localized in a separate optical cavity and linked to other nodes via photonic links such as optical fibers. We derive a model applicable to a wide range of parameters and scenarios to describe the nodes and the local spin-photon interaction accounting for the pulsed (finite bandwidth) nature of flying single photons while optimizing the rate and fidelity. We investigate entanglement generation between remote qubits and tailor protocols to a variety of physical implementations with different properties. Of particular interest is the regime of weak coupling and low cooperativity between spin and cavity which is relevant in the cases of the nitrogen and silicon vacancy centers in diamond. We also take into account the variability of the properties between realistic (stationary) nodes.