摘要：Enhancing the polarization of nuclear spins surrounding the nitrogen-vacancy (NV) center in diamond has recently attracted widespread attention due to its various applications. Here we present an analytical formula that not only provides a clear physical picture for the recently observed polarization reversal of strongly coupled 13C nuclei over a narrow range of magnetic field [H. J. Wang et al. , Nat. Commun. 4, 1940 (2013)], but also demonstrates the possibility to strongly polarize weakly coupled 13C nuclei. This allows sensitive magnetic field control of the 13C nuclear spin polarization for NMR applications and significant suppression of the 13C nuclear spin noise to prolong the NV spin coherence time.
