AI 中文总结
本研究提出连续波量子弛豫测量协议，可在宽范围、宽温度下高效测量$T_1$，能在纳米金刚石中实现定量传感，相比脉冲方法大幅提速，为优化纳米金刚石尺寸提供实用途径。
AI 中文摘要
量子弛豫测量是金刚石中氮-空位（NV）色心乃至更广泛的固态自旋量子比特最成功的应用之一，通过测量自旋-晶格弛豫时间$T_1$实现对磁噪声和顺磁物种的超灵敏检测。然而，传统脉冲协议仅能在有限的时间范围内高效探测$T_1$，这限制了该技术的应用范围和通量。本文提出一种在频域工作的连续波量子弛豫测量协议：通过测量低频微波振幅调制下光探测磁共振信号的频率响应，从自旋系统的特征响应时间中提取$T_1$。该方法可实现跨越三个数量级以上的高效$T_1$测量，本实验中直接验证了从60微秒到200毫秒的测量范围，且能在宽温度范围和显著的系综非均匀性下工作。进一步研究表明，该协议可在纳米金刚石中实现基于弛豫测量的定量传感，相比脉冲方法大幅提速，为优化纳米金刚石尺寸以提升灵敏度提供了实用途径。
英文摘要
Quantum relaxometry is one of the most successful applications of nitrogen-vacancy (NV) centers in diamond and, more broadly, solid-state spin qubits, enabling ultrasensitive detection of magnetic noise and paramagnetic species via measurements of the spin-lattice relaxation time $T_1$. Conventional pulsed protocols, however, probe $T_1$ efficiently only over a limited temporal range, which restricts the scope and throughput of the technique. Here we introduce a continuous-wave quantum relaxometry protocol that operates in the frequency domain. By measuring the frequency response of the optically detected magnetic resonance signal under low-frequency microwave amplitude modulation, we extract $T_1$ from the characteristic response time of the spin system. The method enables efficient $T_1$ measurements spanning more than three orders of magnitude -- directly demonstrated from 60 $μ$s to 200 ms in our experiments -- across a broad temperature range and under substantial ensemble inhomogeneity. We further show that this protocol enables quantitative relaxometry-based sensing in nanodiamonds, achieving a substantial speed-up over the pulsed methods and offering a practical approach to optimizing nanodiamond size for enhanced sensitivity.
Comments25 pages together with supplementary information
