High-fidelity spin and optical control of single silicon vacancy centres in silicon carbide

TL;DR

This paper demonstrates that silicon vacancy centers in silicon carbide exhibit stable optical and spin properties, enabling high-fidelity quantum interfaces without requiring inversion symmetry, thus advancing scalable quantum network technologies.

Contribution

It shows that silicon vacancy centers in silicon carbide have robust optical and spin properties despite lacking inversion symmetry, enabling high-fidelity spin-photon interfaces.

Findings

Stable optical transitions with low inhomogeneous broadening

Electron spin coherence times comparable to diamond NV centers

Coherent hyperfine coupling to single nuclear spins

Abstract

Optically interfaced spins in the solid promise scalable quantum networks. Robust and reliable optical properties have so far been restricted to systems with inversion symmetry. Here, we release this stringent constraint by demonstrating outstanding optical and spin properties of single silicon vacancy centres in silicon carbide. Despite the lack of inversion symmetry, the system's particular wave function symmetry decouples its optical properties from magnetic and electric fields, as well as from local strain. This provides a high-fidelity spin-to-photon interface with exceptionally stable and narrow optical transitions, low inhomogeneous broadening, and a large fraction of resonantly emitted photons. Further, the weak spin-phonon coupling results in electron spin coherence times comparable with nitrogen-vacancy centres in diamond. This allows us to demonstrate coherent hyperfine coupling to single nuclear spins, which can be exploited as qubit memories. Our findings promise quantum network applications using integrated semiconductor-based spin-to-photon interfaces.