Room-temperature in situ nuclear spin hyperpolarization from optically pumped nitrogen vacancy centres in diamond.
Room-temperature in situ nuclear spin hyperpolarization from optically pumped nitrogen vacancy centres in diamond.
复制标题
来自钻石的光学泵送氮空位中心的原位原位核自旋超极化。
DOI：
10.1038/ncomms9965
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发表时间：
2015-12-07
影响因子：
16.6
通讯作者：
Pines A
中科院分区：
文献类型：
--
作者：
King JP;Jeong K;Vassiliou CC;Shin CS;Page RH;Avalos CE;Wang HJ;Pines A
核自旋的弱极化导致的低探测灵敏度是磁共振光谱和成像的主要限制。已经开发出了增强核自旋极化的方法，但它们通常需要高磁场、低温或磁体之间的样品转移。在这里，我们报告了通过高场磁共振观察到的13C核自旋的整体、室温超极化。这项技术利用了室温下金刚石氮空位中心的高光学诱导自旋极化，并结合了动态核极化。我们观察到体核自旋极化为6%，比热平衡提高了170,000∼。用标准的核磁共振探头原位探测到超极化自旋的信号，而不需要样品穿梭或精确的晶体定向。通过光抽运/动态核极化实现的超极化应在任意磁场下起作用，从而使环境条件下固体和液体的核磁共振灵敏度提高数量级。增加核自旋极化的方法可以提高磁共振技术的灵敏度，但它们往往局限于不利的条件。在这里，作者利用金刚石晶体中氮空位中心的光学响应实现了体相13C核自旋的室温超极化。
Low detection sensitivity stemming from the weak polarization of nuclear spins is a primary limitation of magnetic resonance spectroscopy and imaging. Methods have been developed to enhance nuclear spin polarization but they typically require high magnetic fields, cryogenic temperatures or sample transfer between magnets. Here we report bulk, room-temperature hyperpolarization of 13C nuclear spins observed via high-field magnetic resonance. The technique harnesses the high optically induced spin polarization of diamond nitrogen vacancy centres at room temperature in combination with dynamic nuclear polarization. We observe bulk nuclear spin polarization of 6%, an enhancement of ∼170,000 over thermal equilibrium. The signal of the hyperpolarized spins was detected in situ with a standard nuclear magnetic resonance probe without the need for sample shuttling or precise crystal orientation. Hyperpolarization via optical pumping/dynamic nuclear polarization should function at arbitrary magnetic fields enabling orders of magnitude sensitivity enhancement for nuclear magnetic resonance of solids and liquids under ambient conditions. Methods to increase nuclear spin polarization can enhance the sensitivity of magnetic resonance techniques however they are often limited to unfavourable conditions. Here, the authors achieve room temperature hyperpolarization of bulk 13C nuclear spins by exploiting the optical response of nitrogen vacancy centers in diamond crystals.