Photonic indistinguishability of the tin-vacancy center in nanostructured diamond

TL;DR

This paper demonstrates high-purity, highly indistinguishable single-photon emission from tin-vacancy centers in nanostructured diamond, with potential for scalable quantum photonic applications.

Contribution

It reports the generation of near-perfect single photons with high indistinguishability and spectral stability from tin-vacancy centers in nanostructured diamond.

Findings

Single photons with 99.7% purity achieved.

Indistinguishability of 63% demonstrated.

Spectral stability over 100 ms enabling large photon strings.

Abstract

Tin-vacancy centers in diamond are promising spin-photon interfaces owing to their high quantum-efficiency, large Debye-Waller factor, and compatibility with photonic nanostructuring. Benchmarking their single-photon indistinguishability is a key challenge for future applications. Here, we report the generation of single photons with $99.7^{+0.3}_{-2.5}\%$ purity and $63(9)\%$ indistinguishability from a resonantly excited tin-vacancy center in a single-mode waveguide. We obtain quantum control of the optical transition with $1.71(1)$-ns-long $\pi$-pulses of $77.1(8)\%$ fidelity. A modest Purcell enhancement factor of 12 would enhance the indistinguishability to $95$\%. The greater than $100$ ms spectral stability shown would then enable strings of up to $10^6$ identical photons to be generated.