The recently discovered spin defects in hexagonal boron nitride (hBN), a layered van der Waals material, have great potential in quantum sensing. However, the photoluminescence and the contrast of the optically detected magnetic resonance (ODMR) of hBN spin defects are relatively low so far, which limits their sensitivity. Here we report a record-high ODMR contrast of 46% at room temperature and simultaneous enhancement of the photoluminescence of hBN spin defects by up to 17-fold by the surface plasmon of a gold film microwave waveguide. Our results are obtained with shallow boron vacancy spin defects in hBN nanosheets created by low-energy He⁺ ion implantation and a gold film microwave waveguide fabricated by photolithography. We also explore the effects of microwave and laser powers on the ODMR and improve the sensitivity of hBN spin defects for magnetic field detection. Our results support the promising potential of hBN spin defects for nanoscale quantum sensing.

中文翻译：

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用于量子传感的六方氮化硼中的高对比度等离子体增强浅自旋缺陷

最近在六方氮化硼 (hBN) 中发现的自旋缺陷是一种分层的范德华材料，在量子传感方面具有巨大的潜力。然而，迄今为止，hBN自旋缺陷的光致发光和光学检测磁共振（ODMR）的对比度相对较低，这限制了它们的灵敏度。在这里，我们报告了室温下 46% 的创纪录高 ODMR 对比度，同时金膜微波波导的表面等离子体使 hBN 自旋缺陷的光致发光增强了 17 倍。我们的结果是通过低能 He ⁺产生的 hBN 纳米片中的浅硼空位自旋缺陷获得的离子注入和光刻制造的金膜微波波导。我们还探索了微波和激光功率对 ODMR 的影响，并提高了 hBN 自旋缺陷对磁场检测的灵敏度。我们的结果支持 hBN 自旋缺陷在纳米级量子传感方面的潜力。