标题： 氮化硼色心金刚石中磁成像的邻近诱导伪影 显示英文标题

标题： Proximity-induced artefacts in magnetic imaging with nitrogen-vacancy ensembles in diamond

摘要： 基于钻石中氮空位（NV）中心集合的磁成像是一种最近发展的技术，允许定量矢量场映射。 在这里，我们揭示了在磁性样品靠近NV传感层（几纳米）放置时，测量的磁场中出现伪影的来源。 使用磁性纳米颗粒作为测试样品，我们发现测量的磁场在形状、幅度甚至符号上都与计算的磁场有显著偏差。 通过建模完整的测量过程，我们表明这些差异是由于NV传感器的有限测量范围与光学读出的有限空间分辨率共同导致的。 我们数值研究了离焦距离的作用，以确定无伪影的区域，并讨论了其在超薄材料中的应用。 这项工作提供了一个指导，用于预测和减轻基于NV的宽场磁成像中可能出现的接近引起的伪影，同时也表明这些伪影对样品的敏感性可以使它们成为磁表征的有用工具。 显示英文摘要

摘要： Magnetic imaging with ensembles of nitrogen-vacancy (NV) centres in diamond is a recently developed technique that allows for quantitative vector field mapping. Here we uncover a source of artefacts in the measured magnetic field in situations where the magnetic sample is placed in close proximity (a few tens of nm) to the NV sensing layer. Using magnetic nanoparticles as a test sample, we find that the measured field deviates significantly from the calculated field, in shape, amplitude and even in sign. By modelling the full measurement process, we show that these discrepancies are caused by the limited measurement range of NV sensors combined with the finite spatial resolution of the optical readout. We numerically investigate the role of the stand-off distance to identify an artefact-free regime, and discuss an application to ultrathin materials. This work provides a guide to predict and mitigate proximity-induced artefacts that can arise in NV-based wide-field magnetic imaging, and also demonstrates that the sensitivity of these artefacts to the sample can make them a useful tool for magnetic characterisation.