Abstract: Quantum networks and sensing require solid-state spin-photon interfaces that combine single-photon generation and long-lived spin coherence with scalable device integration, ideally at ambient conditions. Despite rapid progress reported across several candidate systems, those possessing quantum coherent single spins at room temperature remain extremely rare.

In this talk, I will show quantum coherent control under ambient conditions of a single-photon emitting defect in hexagonal boron nitride [1]². I will show how this carbon-related defect has a spin-triplet electronic ground-state manifold. I will reveal that the spin coherence is governed predominantly by coupling to only a few proximal nuclei and is prolonged by decoupling protocols. Finally, show how these results open routes to explore this defect type for nanoscale magnetometry [3].

[1] Stern, H.L., M. Gilardoni, C., Gu, Q. et al. A quantum coherent spin in hexagonal boron nitride at ambient conditions. Nat. Mater. 23, 1379–1385 (2024).

[2] Stern, H.L., Gu, Q., Jarman, J. et al. Room-temperature optically detected magnetic resonance of single defects in hexagonal boron nitride. Nat Commun 13, 618 (2022).

[3] Gilardoni, C. M., Eizagirre Barker, S., Curtin, C. L., Fraser, S. A., Powell, O. F.J., Lewis, D. K., Deng, X., Ramsay, A. J., Li, C., Aharonovich, I., Tan, H. H., Atatüre, M. and Stern, H. L.. arXiv.:2408.10348 (2024).