发表机构
National Institute of Technology Calicut（国立卡利卡特技术学院）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究提出基于一维YIG/CoFeB磁振子晶体的芯片式NV磁强计，通过磁振子腔增强灵敏度，预测临界耦合读出下灵敏度达93 pT/√Hz，明确了天线耦合等关键设计参数。
AI 中文摘要
氮空位（NV）中心系综是领先的室温磁强计，但其灵敏度通常从单一共振提取，依赖外部微波和偏置场硬件。本研究提出一种基于芯片的NV磁强计，其核心为一维YIG/CoFeB磁振子晶体，其中单个结构缺陷构成无源磁振子腔，集成永磁体提供偏置场。微磁模拟显示，在2.5-3.0 GHz的磁振子带隙内存在缺陷局域的自旋波模式，频率为2.910 GHz，与NV零场分裂相差40 MHz，其能带结构与独立平面波计算结果匹配。采用Tavis-Cummings/Lindblad模型（微波通过该模式到达NV系综）预测，超精细分辨的光探测磁共振谱仅在模式线宽内较强，且存在色散零差响应，每个¹⁴N超精细线对应一个陡峭边缘。主方程解与闭式零差稳态（R²>0.9999）及近似解析ODMR理论（峰位置误差在0.012 MHz内）吻合。对于采用室温电子学的临界耦合读出，结合三个边缘可实现93 pT/√Hz的预测灵敏度，比最佳单边缘提升√3倍。绘制灵敏度随NV-磁振子耦合的变化曲线，发现最优值在g_ens/2π≈0.2-0.4 MHz附近，其中自旋线宽为0.64 MHz时灵敏度达72 pT/√Hz，自旋线宽为0.17 MHz时达19 pT/√Hz，热极限分别为6.6和1.7 pT/√Hz。因此，天线模式耦合、NV-磁振子耦合及自旋线宽是主要设计调控参数。
英文摘要
Nitrogen-vacancy (NV) centre ensembles are leading room-temperature magnetometers, but their sensitivity is usually extracted from a single resonance and relies on external microwave and bias-field hardware. This work proposes a chip-scale NV magnetometer built around a one-dimensional YIG/CoFeB magnonic crystal, in which a single structural defect forms a passive magnonic cavity and integrated permanent magnets supply the bias field. Micromagnetic simulations show a defect-localised spin-wave mode at 2.910 GHz inside the 2.5-3.0 GHz magnonic band gap, 40 MHz from the NV zero-field splitting, with a band structure that matches an independent plane-wave calculation. A Tavis-Cummings/Lindblad model in which the microwave reaches the NV ensemble through this mode predicts a hyperfine-resolved optically detected magnetic resonance spectrum that is strong only within the mode linewidth, and a dispersive homodyne response with one steep edge per $^{14}$N hyperfine line. The master-equation solutions agree with the closed-form homodyne steady state ($R^2 > 0.9999$) and with an approximate analytic ODMR theory (peak positions within 0.012 MHz). For a critically coupled readout with room-temperature electronics, combining the three edges gives a projected sensitivity of 93 pT/$\sqrt{\rm Hz}$, a $\sqrt{3}$-fold gain over the best single edge. Mapping the sensitivity against the NV-magnon coupling reveals an optimum near $g_{\rm ens}/2π\approx 0.2$-$0.4$ MHz, where it reaches 72 pT/$\sqrt{\rm Hz}$ for a 0.64 MHz spin linewidth and 19 pT/$\sqrt{\rm Hz}$ for 0.17 MHz, with thermal limits of 6.6 and 1.7 pT/$\sqrt{\rm Hz}$. The antenna-mode coupling, the NV-magnon coupling and the spin linewidth are therefore the main design levers.
