High field magnetometry with hyperpolarized nuclear spins

Quantum sensors have attracted broad interest in the quest towards sub-micronscale NMR spectroscopy. Such sensors predominantly operate at low magnetic fields. Instead, however, for high resolution spectroscopy, the high-field regime is naturally advantageous because it allows high absolute chemical shift discrimination. Here we demonstrate a high-field spin magnetometer constructed from an ensemble of hyperpolarized C-13 nuclear spins in diamond. They are initialized by Nitrogen Vacancy (NV) centers and protected along a transverse Bloch sphere axis for minute-long periods. When exposed to a time-varying (AC) magnetic field, they undergo secondary precessions that carry an imprint of its frequency and amplitude. For quantum sensing at 7T, we demonstrate detection bandwidth up to 7 kHz, a spectral resolution <100 mHz, and single-shot sensitivity of 410pT/root Hz. This work anticipates opportunities for microscale NMR chemical sensors constructed from hyperpolarized nanodiamonds and suggests applications of dynamic nuclear polarization (DNP) in quantum sensing.

Automated summary

This study demonstrates a high-field spin magnetometer constructed from hyperpolarized C-13 nuclear spins, achieving high-resolution quantum sensing through the detection of its secondary precession. This work anticipates new opportunities for constructing microscale NMR chemical sensors using hyperpolarized nanodiamonds and suggests applications of dynamic nuclear polarization in quantum sensing.