42. High-Field Magnetometry with Hyperpolarized Nuclear Spins

O. Sahin, E. d. L. Sanchez, S. Conti, A. Akkiraju, P. Reshetikhin, E. Druga, A. Aggarwal, B. Gilbert, S. Bhave, A. Ajoy* [PDF] [SI]
arXiv:2112.11612 — Nature Communications 13, 5486 (2022)

Selected as Editors Highlight by Nature Communications
Spotlighted by News & Views in Nature Physics: Magnetometry goes nuclear [pdf]

Abstract:
Quantum sensors have attracted broad interest in the quest towards submicronscale NMR spectroscopy. Such sensors predominantly operate at low magnetic fields. Instead, however, for high resolution spectroscopy, the highfield 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 13C 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 timevarying (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/ √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.