Degen leads the Spin Physics and Imaging group, one of the world's leading NV-center magnetometry labs. Research directions (as of 2025): (1) Scanning NV magnetometry of quantum materials — NV-tipped cantilevers image current flow (≲50 nm resolution) in graphene heterostructures and resolve domain walls in antiferromagnets/ferroelectrics; cryogenic scanning down to 350 mK in dilution refrigerator (published Appl. Phys. Lett. 2022). (2) Single-molecule NMR — shallow NV centers detect nuclear spins from surface-adsorbed molecules with sub-nanometer 3D resolution; 2022 Nano Lett. on amine-functionalized diamond surfaces; exploring chirality-induced spin selectivity at few-molecule level. (3) NV magnetometry protocols — reconstruction-free waveform sensing (1.1 ns time resolution, Nature 2025), gradiometric detection, spectrum demodulation for rapid scanning, multi-NV addressing. (4) Diamond nanoengineering — multicone pillar waveguides, surface engineering, scanning probe fabrication. ERC Proof-of-Concept 2025 for photonic IC single-photon NV excitation/detection for commercial quantum sensing.

Feldman's group uses scanning NV-diamond magnetometry -- imaging local magnetic fields with a single spin at the tip of a scanning probe -- to visualize currents, magnetism, and correlated-electron order in moire and other quantum materials at the nanoscale, extending the sensitivity/resolution tradeoff of ensemble NV-diamond sensing (DEER/T1 protocols at pT/√Hz) down to single-spin, single-defect imaging.

Yacoby's lab develops scanning-probe quantum sensors, most notably scanning single-NV-center magnetometers and SQUID-on-tip probes, to image nanoscale magnetic textures and current flow in quantum materials at cryogenic and millikelvin temperatures. This scanning-probe approach extends the sensitivity and spatial resolution of NV ensemble quantum sensing experiments (DEER, nanoscale NMR, T1 relaxometry), which established pT/√Hz-class magnetometry, down to single-spin, nanometer-scale imaging of individual quantum materials.