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arXiv 1802.09635cond-mat.mes-hall
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金刚石中氮空位中心的光学探测及其在不同外场条件下的宽带EPR光谱研究

Broadband EPR Spectroscopy in Diverse Field Conditions Using Optically Detected Nitrogen-Vacancy Centers in Diamond

C. M. Purser, V. P. Bhallamudi, C. S. Wolfe, H. Yusuf, B. A. McCullian, C. Jayaprakash, M. E. Flatté, P. C. Hammel

摘要:

顺磁磁共振是一种用于表征和识别化学目标的强大技术,越来越多地用于成像;然而,室温下的低自旋极化和中等磁场对检测少量自旋提出了挑战。在这项工作中,我们使用荧光从氮空位(NV)中心在金刚石检测电子顺磁共振(EPR)光谱的光学非活性的目标自旋在各种条件下的字段大小和方向。该协议既不需要直接微波操纵的NV自旋,也不NV和目标自旋共振之间的光谱重叠,从而使宽带检测。这种意想不到的非共振耦合是由于一个双声子的过程,放松NV自旋接近目标自旋的波动偶极矩,这表明灵敏度是由偶极偶极耦合强度。这种方法有望用于灵敏的EPR检测,特别是在难以控制金刚石晶体取向的环境中。这尤其适用于生物传感应用,其中纳米金刚石因其明亮,稳定的荧光和生物相容性而受到追捧。

英文摘要:

Paramagnetic magnetic resonance, a powerful technique for characterizing and identifying chemical targets, is increasingly used for imaging; however, low spin polarization at room temperature and moderate magnetic fields poses challenges for detecting small numbers of spins. In this work, we use fluorescence from nitrogen-vacancy (NV) centers in diamond to detect the electron paramagnetic resonance (EPR) spectrum of optically inactive target spins under various conditions of field magnitude and orientation. The protocol requires neither direct microwave manipulation of the NV spins nor spectral overlap between NV and target spin resonances, thus enabling broadband detection. This unexpected non-resonant coupling is attributable to a two-phonon process that relaxes NV spins proximate to the fluctuating dipole moment of the target spin, suggesting that the sensitivity is determined by the dipole-dipole coupling strength. This approach holds promise for sensitive EPR detection, particularly in settings where control over the diamond-crystal orientation is difficult. This is notably the case for biological sensing applications, where nanodiamonds are being pursued for their bright, stable fluorescence and biocompatibility.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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