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.

Wrachtrup is a founder of NV-centre quantum sensing: single-spin and ensemble magnetometry, nanoscale/single-molecule NMR and ESR, nuclear-spin registers, scanning-probe quantum-materials imaging, and programmable diamond nanosensors for chemistry and biology. His group actively recruits postdocs across NV sensing and quantum technology. In the broader landscape of NV-centre ensemble quantum sensing (DEER, nano-NMR, T1 relaxometry) operating near pT/sqrt(Hz) sensitivity, this work is the reference point, extending DEER/nano-NMR toward single-molecule and cryogenic regimes.