AI 中文总结
本研究采用六方氮化硼中VB-量子传感器的自旋共振频率追踪技术，实现了亚微米分辨率的三维磁映射，将磁成像采集时间缩短至少一个数量级。
AI 中文摘要
六方氮化硼（hBN）中带负电的硼空位中心（$V^-_B$）的自旋依赖发光特性的发现，为范德华材料量子传感开辟了新平台。特别是，用于确定hBN色心电子自旋共振（ESR）频率的光探测磁共振（ODMR）技术，成为实现亚微米分辨率磁场量子传感的重要工具。然而，由于ODMR对比度较低，当前用于绘制直流磁场图的技术需要数小时的积分时间才能获取微米级区域的磁图像。本研究中，我们报告了一种频率追踪方法的实现，用于实时监测hBN中局域$V^-_B$中心的ESR频率。利用该技术，磁场监测可在短短数分钟内绘制出微米级锥形磁尖端产生的磁场图案。通过控制磁性样品相对于量子传感器的位置，实现了衍射极限分辨率的磁场三维映射，达到了 shot-noise-limited 灵敏度54 μT/√Hz。我们的系统测得的磁场梯度为3.6±0.2 μT/nm，最大检测磁场速率为6 mT/s。本研究结果证实，自旋共振频率追踪是一种可行的技术和快速的磁成像方法，与传统技术相比，采集时间至少缩短了一个数量级。
英文摘要
The discovery of spin-dependent luminescent properties of negatively charged boron-vacancy centers ($V^-_B$) in hexagonal boron nitride (hBN) enabled a new platform for quantum sensing with van der Waals materials. Particularly, the possibility of performing optically detected magnetic resonance (ODMR) for determining the electron spin resonance (ESR) frequencies of hBN color centers became a strong tool for quantum sensing of magnetic fields with submicrometric resolution. However, due to low ODMR contrast, current techniques proposed for mapping DC magnetic fields require hours of integration to obtain a magnetic image of a micron-sized region. In this work, we report the implementation of a frequency-tracking approach for real-time monitoring of ESR frequencies of localized $V^-_B$ centers in hBN. With this technique, magnetic field monitoring was used to map the field pattern generated by a micron-sized conical magnetic tip in only a few minutes. By controlling the magnetic sample's position relative to the quantum sensor, three-dimensional magnetic mapping of the field was achieved with diffraction-limited resolution and shot-noise-limited sensitivity of 54 $μ$T$/\sqrt{\text{Hz}}$. Magnetic field gradients of 3.6 $\pm$ 0.2 $μ$T/nm were measured with our system, in which a maximum detected field rate of 6 mT/s was achieved. The results of this study establish spin resonance frequency-tracking as a viable technique and fast method for minute-scale magnetic imaging, reducing acquisition times by at least one order of magnitude if compared to conventional techniques.
