Single-Photon Switching and Entanglement of Solid-State Qubits in an Integrated Nanophotonic System

TL;DR

This paper demonstrates a scalable integrated nanophotonic platform using silicon-vacancy centers in diamond for single-photon switching, tunable photon sources, and entanglement generation, advancing quantum network capabilities.

Contribution

It introduces an integrated diamond-based system with SiV centers for efficient photon control, single-photon sources, and entanglement, enabling scalable quantum photonic devices.

Findings

Single-photon optical switching controlled by SiV centers.

Tunable single-photon source with adjustable frequency and bandwidth.

Entanglement between SiV centers verified via superradiant photon correlation.

Abstract

Efficient interfaces between photons and quantum emitters form the basis for quantum networks and enable nonlinear optical devices operating at the single-photon level. We demonstrate an integrated platform for scalable quantum nanophotonics based on silicon-vacancy (SiV) color centers coupled to nanoscale diamond devices. By placing SiV centers inside diamond photonic crystal cavities, we realize a quantum-optical switch controlled by a single color center. We control the switch using SiV metastable orbital states and verify optical switching at the single-photon level by using photon correlation measurements. We use Raman transitions to realize a single-photon source with a tunable frequency and bandwidth in a diamond waveguide. Finally, we create entanglement between two SiV centers by detecting indistinguishable Raman photons emitted into a single waveguide. Entanglement is verified using a novel superradiant feature observed in photon correlation measurements, paving the way for the realization of quantum networks.