Research Data for the publication titled "Impact of irradiation conditions on the magnetic field sensitivity of spin defects in hBN nano flakes"

Abstract for the paper : We study V_B⁻ centres generated by helium focused ion beam (FIB) irradiation in thin (~70 nm) hBN nanoflakes, in order to investigate the effect of implantation conditions on the key parameters that influence the magnetic field sensitivity of V_B⁻ quantum sensors. Using a combination of photoluminescence, optically detected magnetic resonance, and Raman spectroscopy, we examine the competing factors of maximizing signal intensity through larger V_B⁻ concentration against the degradation in spin coherence and lattice quality observed at high ion fluences.Our results indicate that both the V_B⁻ spin properties and hBN lattice parameters are largely preserved up to an ion fluence of 10¹⁴ ions cm⁻², beyond which significant degradation occurs in both. At the optimal implantation dose, an AC magnetic sensitivity of approximately 1 μT / √Hz is achieved. Using the patterned implantation enabled by the FIB, we find that V_B⁻ centres and the associated lattice damage are well localized to the implanted regions. This work demonstrates how careful selection of fabrication parameters can be used to optimize the properties of V_B⁻ centres in hBN, supporting their application as quantum sensors based in two-dimensional materials.

论文摘要：本研究针对厚度约70 nm的六方氮化硼（hBN）纳米片，探究氦聚焦离子束（FIB）辐照产生的负硼空位（V_B⁻）中心，旨在揭示注入工艺条件对影响V_B⁻量子传感器磁场灵敏度的关键参数的调控机制。本研究结合光致发光、光探测磁共振与拉曼光谱技术，对两大竞争因素展开分析：一方面通过提升V_B⁻浓度以最大化信号强度，另一方面高离子注量会引发自旋相干性退化与晶格质量劣化。研究结果显示，当离子注量不超过10¹⁴ ions·cm⁻²时，V_B⁻的自旋特性与hBN晶格参数均可得到较好保留；当注量超出该阈值后，二者均会出现显著退化。在最优注入剂量下，可实现约1 μT/√Hz的交流磁场灵敏度。借助FIB的图案化辐照能力，本研究发现V_B⁻中心与相关晶格损伤均精准局限于辐照区域内。本工作证实，通过精准选择制备参数可优化hBN中V_B⁻中心的性能，为其作为二维材料基量子传感器的应用提供了有力支撑。