Probing Boron Vacancy Defects in hBN via Single Spin Relaxometry

Alex L. Melendez; Ruotian Gong; Guanghui He; Yan Wang; Yueh-Chun Wu; Thomas Poirier; Steven Randolph; Sujoy Ghosh; Liangbo Liang; Stephen Jesse; An-Ping Li; Joshua T. Damron; Benjamin J. Lawrie; James H. Edgar; Ivan V. Vlassiouk; Chong Zu; Huan Zhao

arXiv · 2504.09432

Probing Boron Vacancy Defects in hBN via Single Spin Relaxometry

Alex L. Melendez·Ruotian Gong·Guanghui He·Yan Wang·Yueh-Chun Wu·Thomas Poirier·Steven Randolph·Sujoy Ghosh·Liangbo Liang·Stephen Jesse·An-Ping Li·Joshua T. Damron·Benjamin J. Lawrie·James H. Edgar·Ivan V. Vlassiouk·Chong Zu·Huan Zhao

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Abstract

Spin defects in solids offer promising platforms for quantum sensing and memory due to their long coherence times and optical addressability. Here, we integrate a single nitrogen-vacancy (NV) center in diamond with scanning probe microscopy to discover, read out, and spatially map arbitrary spin-based quantum sensors at the nanoscale. Using the boron vacancy ($\mathrm{V}_\mathrm{B}^-$) center in hexagonal boron nitride$\unicode{x2013}$an emerging two-dimensional spin system$\unicode{x2013}$as a model, we detect its electron spin resonance indirectly via changes in the spin relaxation time ($T_1$) of a nearby NV center, eliminating the need for optical excitation or fluorescence detection of the $\mathrm{V}_\mathrm{B}^-$. Cross-relaxation between NV and $\mathrm{V}_\mathrm{B}^-$ ensembles significantly reduces NV $T_1$, enabling quantitative nanoscale mapping of defect densities beyond the optical diffraction limit and clear resolution of hyperfine splitting in isotopically enriched h$^{10}$B$^{15}$N. Our method demonstrates interactions between 3D and 2D spin sensors, establishing NV centers as versatile probes for characterizing otherwise inaccessible spin defects.

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Alex L. Melendez, Ruotian Gong, Guanghui He, Yan Wang, Yueh-Chun Wu, Thomas Poirier, Steven Randolph, Sujoy Ghosh, Liangbo Liang, Stephen Jesse, An-Ping Li, Joshua T. Damron, Benjamin J. Lawrie, James H. Edgar, Ivan V. Vlassiouk, Chong Zu, Huan Zhao. 2026-03-05. Probing Boron Vacancy Defects in hBN via Single Spin Relaxometry. https://arxiv.org/abs/2504.09432

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