Revealing and controlling surface electric field noise in hBN via shallow boron vacancies
Phys. Rev. B 113, 104110 – Published 25 March, 2026
DOI: https://doi.org/10.1103/vc1g-wr7t
Abstract
Hexagonal boron nitride (hBN) spin defects offer transformative potential for quantum sensing through atomic-scale proximity to target samples, yet their performance is fundamentally limited by rapid coherence loss. While magnetic noise mechanisms have been extensively studied, another critical influence from surface electric field noise remains unexplored in hBN systems. Here, we employ shallow boron vacancies as in situ quantum sensors using the double-quantum relaxation method, demonstrating a depth-related power-law frequency dependence of the noise. The relaxation rate is independent of implantation fluence, and shows a noticeable rise as the temperature increases from 296 K to 453 K, evidencing a thermal contribution. Using glycerol treatment to selectively suppress electric field fluctuations via its high dielectric constant, we effectively reduce the electric field noise intensity by more than 30%, and quantify the lower bound of vertical surface charge noise as about V/m. Our work provides the direct quantification of hBN surface electric field noise.