Double-quantum enhanced coherent control and magnetic sensing of spin defects in hexagonal boron nitride

arXiv:2611.13447v1 Announce Type: new Abstract: The negatively charged boron vacancy ($V_{\mathrm{B}}^{-}$) in hexagonal boron nitride (hBN) is a promising spin defect for quantum sensing in two-dimensional material systems. Previous hBN experiments have mainly exploited the two spin-triplet ground-state single-quantum transitions separately. Here we implement a double-quantum driving scheme based on simultaneous resonant microwave excitation of both ground-state single-quantum transitions, establishing coherent control of the $\Delta m_s=2$ manifold in a $V_{\mathrm{B}}^{-}$ ensemble. We compare the resulting double-quantum response with the corresponding single-quantum protocol under identical experimental conditions.