Strongly polarizing weakly coupled $^{13}$C nuclear spins with optically pumped nitrogen-vacancy center

TL;DR

This paper develops an analytical theory to optimize dynamic nuclear polarization of $^{13}$C nuclei near NV centers in diamond, enabling enhanced control and noise suppression for quantum sensing and NMR applications.

Contribution

It provides a parameter-free analytical model explaining polarization dependence and demonstrates strong polarization of weakly coupled nuclei under specific conditions.

Findings

Explains polarization dependence on magnetic field for strongly coupled nuclei.

Shows possibility of polarizing weakly coupled $^{13}$C nuclei with weak optical pumping.

Enables magnetic control of nuclear spin polarization for improved quantum sensing.

Abstract

Enhancing the polarization of nuclear spins surrounding the nitrogen-vacancy (NV) center in diamond has attracted widespread attention recently due to its various applications. Here we present an analytical theory and comprehensive understanding on how to optimize the dynamic nuclear polarization by an optically pumped NV center near the ground state level anticrossing. Our results not only provide a parameter-free explanation and a clearly physics picture for the recently observed polarization dependence on the magnetic field for strongly coupled $^{13}$C nuclei [H. J. Wang \textit{et al}., Nat. Commun. 4, 1 (2013)], but also demonstrate the possibility to strongly polarize weakly coupled $^{13}$C nuclei under weak optical pumping and suitably chosen magnetic field. This allows sensitive magnetic control of the $^{13}$C nuclear spin polarization for NMR applications and significant suppression of the $^{13}$C nuclear spin noise to prolong the NV spin coherence time.