An integrated nanophotonic quantum register based on silicon-vacancy spins in diamond

TL;DR

This paper demonstrates a quantum network node using silicon-vacancy spins in diamond nanocavities, achieving long coherence times and entanglement between spins and photons for potential quantum communication applications.

Contribution

It introduces experimental techniques for controlling SiV spins in diamond nanocavities and demonstrates entanglement generation between spins and photons, advancing integrated quantum network nodes.

Findings

Achieved 100 ms coherence times for nuclear spins.

Generated Bell states between SiV spins and photons.

Controlled SiV-nanocavity system for quantum networking.

Abstract

We realize an elementary quantum network node consisting of a silicon-vacancy (SiV) color center inside a diamond nanocavity coupled to a nearby nuclear spin with 100 ms long coherence times. Specifically, we describe experimental techniques and discuss effects of strain, magnetic field, microwave driving, and spin bath on the properties of this 2-qubit register. We then employ these techniques to generate Bell-states between the SiV spin and an incident photon as well as between the SiV spin and a nearby nuclear spin. We also discuss control techniques and parameter regimes for utilizing the SiV-nanocavity system as an integrated quantum network node.