Nitrogen‑Vacancy Centers as Versatile Quantum Sensors for Nanoscale Metrology

Nitrogen-vacancy (NV) centers in diamond are among the most powerful solid-state quantum sensors, but two bottlenecks still define their frontier: how fast a sensor can respond to a signal, and how far NV-based magnetic resonance can be pushed toward structural information for external spins and molecules. In this thesis-prize talk, I present my PhD results addressing both limits, spanning theory, computation, device fabrication, and experiments.

First, I demonstrate ultrafast detection of transient magnetic bursts with a single NV center. Using a composite control sequence designed to operate at the NV’s quantum speed limit, I achieve ~1 ns time resolution together with <20 ps timing precision, enabling time-resolved nanoscale magnetometry of fast spin dynamics under ambient conditions competitive with state-of-the-art synchrotron X-ray techniques.

Then, I advance NV-based NMR toward “structure”, not only “detection”. By combining weak quantum measurements with Fourier and multidimensional spectroscopy, I localize multiple nearby ¹³C nuclear spins and resolve their mutual couplings. In particular, spectral editing isolates ¹³C–¹³C dipolar interactions, providing distance- and orientation-sensitive signatures of nuclear spin pairs, an essential ingredient for nanoscale structural analysis.

Finally, I extend NV-NMR beyond the diamond host by engineering a mixed nitrogen/oxygen surface termination that improves coherence of <10 nm deep NVs while enabling chemical control of adsorbates. With these stabilized sensors, I detect ¹⁹F NMR from covalently attached fluorinated molecules in the ~50–100 molecule regime, marking a key step toward single-molecule-scale spectroscopy at diamond surfaces. We discuss challenges arising from a direct translation of protocols to the surface that were initially developed for NV-NMR inside the diamond host.

The demonstrated improvements in speed, sensitivity, and molecular interfacing underscore the NV center’s unique potential to address longstanding challenges in quantum metrology, chemical analysis, and materials science.