Quiney (currently Head of School) is a theorist of coherent imaging and relativistic atomic structure. His signature contribution is the theory of X-ray free-electron-laser imaging of single particles, including the modelling of radiation damage and ionisation dynamics during the pulse — the question of whether you can extract structure faster than you destroy it — plus phase-retrieval algorithms for coherent diffractive imaging and ptychography. He also works on relativistic quantum chemistry and atomic structure. Positioned against the established body of NV-ensemble quantum sensing work — DEER, nanoscale NMR and T1 relaxometry protocols operating at pT/sqrt(Hz) field sensitivity — the connection is methodological rather than physical: his group develops the inverse-problem and photon-budget theory that governs how much information can be pulled out of a shot-noise-limited measurement, which is the same limit that fixes pT/sqrt(Hz) performance in NV ensembles. Theory-first PI with strong coupling to experimental synchrotron/XFEL programmes.

Witte's group builds table-top extreme-ultraviolet sources via high-harmonic generation and combines them with coherent diffractive imaging (ptychography) to visualize 3D nanostructures, such as multilayer IC features, at resolutions well below the diffraction limit of visible light. The lab also works on lensless microscopy, photoacoustic imaging/metrology, and ultrafast electron/HHG dynamics, sitting at the interface of fundamental attosecond-adjacent light-matter physics and applied nanometrology; the group is actively hiring as it ramps up at TU Delft.