Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.
Nat Commun. 2013;4:1940. doi: 10.1038/ncomms2930.
Dynamic nuclear polarization, which transfers the spin polarization of electrons to nuclei, is routinely applied to enhance the sensitivity of nuclear magnetic resonance. This method is particularly useful when spin hyperpolarization can be produced and controlled optically or electrically. Here we show complete polarization of nuclei located near optically polarized nitrogen-vacancy centres in diamond. Close to the ground-state level anti-crossing condition of the nitrogen-vacancy electron spins, (13)C nuclei in the first shell are polarized in a pattern that depends sensitively upon the magnetic field. Based on the anisotropy of the hyperfine coupling and of the optical polarization mechanism, we predict and observe a reversal of the nuclear spin polarization with only a few millitesla change in the magnetic field. This method of magnetic control of high nuclear polarization at room temperature can be applied in sensitivity enhanced nuclear magnetic resonance of bulk nuclei, nuclear-based spintronics, and quantum computation in diamond.
动态核极化（Dynamic nuclear polarization）可将电子的自旋极化转移到原子核，从而常规性地提高核磁共振的灵敏度。当自旋超极化可通过光学或电学方式产生和控制时，该方法尤为有用。在此，我们展示了位于金刚石中光学极化氮空位中心附近的原子核的完全极化。在氮空位电子自旋接近基态能级交叉条件下，第一壳层中的（13）C 原子核的极化图案对磁场非常敏感。基于超精细耦合和光学极化机制的各向异性，我们预测并观察到，仅磁场发生几毫特斯拉的变化，核自旋极化就会发生反转。这种在室温下对高核极化进行磁控制的方法可应用于基于核的自旋电子学和金刚石中的量子计算等领域中的基于核的自旋电子学和量子计算等领域中的灵敏度增强核磁共振。
