Pioneer in nanocrystal science. Sensing-relevant directions: (1) coherent Er spin defects in colloidal nanocrystal hosts as scalable solid-state spin qubit platform (2024 paper with Awschalom); (2) size- and shape-controlled nanocrystal synthesis for mid-IR sensing applications; (3) fundamental scaling laws governing optical properties for sensor design. Founder Nanosys and Quantum Dot Corp.

Crozier holds a joint Physics/Electrical Engineering chair and runs a nanophotonics laboratory spanning plasmonic and dielectric metasurfaces, on-chip optical trapping and manipulation of nanoparticles and cells, mid-infrared spectroscopy and detection with metasurface-enhanced and colloidal-nanocrystal devices, and light emission from 2D semiconductors. The unifying theme is engineering the local optical density of states to increase the signal available from a very small number of emitters or molecules. 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 plasmonic and dielectric antenna work is the same physics used to raise photon collection efficiency and hence the shot-noise floor of NV-ensemble magnetometers operating at pT/sqrt(Hz). Note: a substantial fraction of the group's output is device fabrication rather than sensitivity-limited measurement, which is a caveat against the stated preference.

Develops colloidal semiconductor nanocrystal platforms for infrared detection and sensing. Directions: (1) HgTe and HgSe colloidal quantum dot mid-IR photodetectors operating at room temperature — record sensitivity for solution-processed IR sensors; (2) electro-optic modulation using nanocrystal films at ultrafast timescales; (3) fundamental optical and transport properties of doped nanocrystals. Primary application: low-cost infrared imaging and chemical sensing.