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 address this challenge and systematically investigate surface electric field noise in hBN using shallow boron vacancy defects. The double-quantum spin relaxation behavior in response to magnetic fields and defect depths is examined, revealing that the relaxation rate follows a distinctive depth-related power-law dependence of ODMR splitting frequency. The relaxation is also demonstrated to be independent of the defect concentrations. Furthermore, the temperature dependence of the relaxation rate is investigated, showing a noticeable rise as the temperature increases from 296 K to 453 K, thus highlighting the influence of thermal effects on spin relaxation. To further suppress surface electric field noise, we explore the effectiveness of passivation materials, including glycerol and PMMA. Notably, PMMA is more efficient in mitigating surface electric field noise. These experiments enhance the understanding of surface electric field noise in hBN and provide a foundation for developing noise mitigation strategies in future research.

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 address this challenge and systematically investigate surface electric field noise in hBN using shallow boron vacancy defects. The double-quantum spin relaxation behavior in response to magnetic fields and defect depths is examined, revealing that the relaxation rate follows a distinctive depth-related power-law dependence of ODMR splitting frequency. The relaxation is also demonstrated to be independent of the defect concentrations. Furthermore, the temperature dependence of the relaxation rate is investigated, showing a noticeable rise as the temperature increases from 296 K to 453 K, thus highlighting the influence of thermal effects on spin relaxation. To further suppress surface electric field noise, we explore the effectiveness of passivation materials, including glycerol and PMMA. Notably, PMMA is more efficient in mitigating surface electric field noise. These experiments enhance the understanding of surface electric field noise in hBN and provide a foundation for developing noise mitigation strategies in future research.

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 address this challenge and systematically investigate surface electric field noise in hBN using shallow boron vacancy defects. The double-quantum spin relaxation behavior in response to magnetic fields and defect depths is examined, revealing that the relaxation rate follows a distinctive depth-related power-law dependence of ODMR splitting frequency. The relaxation is also demonstrated to be independent of the defect concentrations. Furthermore, the temperature dependence of the relaxation rate is investigated, showing a noticeable rise as the temperature increases from 296 K to 453 K, thus highlighting the influence of thermal effects on spin relaxation. To further suppress surface electric field noise, we explore the effectiveness of passivation materials, including glycerol and PMMA. Notably, PMMA is more efficient in mitigating surface electric field noise. These experiments enhance the understanding of surface electric field noise in hBN and provide a foundation for developing noise mitigation strategies in future research.

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 address this challenge and systematically investigate surface electric field noise in hBN using shallow boron vacancy defects. The double-quantum spin relaxation behavior in response to magnetic fields and defect depths is examined, revealing that the relaxation rate follows a distinctive depth-related power-law dependence of ODMR splitting frequency. The relaxation is also demonstrated to be independent of the defect concentrations. Furthermore, the temperature dependence of the relaxation rate is investigated, showing a noticeable rise as the temperature increases from 296 K to 453 K, thus highlighting the influence of thermal effects on spin relaxation. To further suppress surface electric field noise, we explore the effectiveness of passivation materials, including glycerol and PMMA. Notably, PMMA is more efficient in mitigating surface electric field noise. These experiments enhance the understanding of surface electric field noise in hBN and provide a foundation for developing noise mitigation strategies in future research.