On-demand generation of neutral silicon vacancy centers in diamond

Neutral silicon vacancy centers in diamond are promising candidates for quantum networks because of their excellent optical properties and long spin coherence times¹. However, stabilizing the neutral charge state of silicon vacancy centers so far required high purity, boron doped diamond, which is not a readily available material. Here, we demonstrate two distinct approaches to on-demand generation of neutral silicon vacancy centers. In the first approach, we show that chemical control of the diamond surface can be used to tune the charge state of shallow silicon vacancy centers². We demonstrate reversible charge state tuning of silicon vacancy centers by toggling the surface between hydrogen termination and oxygen termination. In the second approach, we harness itinerant carriers formed by ionizing nearby defects, and we show that the neutral silicon vacancy center can be stabilized by capturing optically generated holes from nearby defects³. Controlling the charge state via surface control and carrier capture offers a route for scalable technologies based on neutral silicon vacancy centers, as well as charge state engineering of other defects.

1. “Observation of an environmentally insensitive solid-state spin defect in diamond”, Rose et al., Science 361, 60-63 (2018)

2. “Neutral silicon vacancy centers in undoped diamond via surface control”, Zhang et al., arXiv:2206.13698 (2022)

3. “Neutral silicon vacancy centers in diamond via photoactivated itinerant carriers”, Zhang et al., arXiv:2209.08710 (2022)