Experimental astroparticle physicist developing novel quantum-limited detectors for dark matter and neutrino sensing. Directions: (1) COHERENT experiment — first measurement of coherent elastic neutrino-nucleus scattering (CEvNS) and ongoing precision measurements; (2) bubble chamber and scintillating bolometer detectors for WIMP dark matter; (3) development of low-threshold detectors sensitive to sub-GeV dark matter; (4) nuclear recoil sensing at the few-eV threshold. Enrico Fermi Institute member.
Fruth is an experimentalist on LZ, the world-leading liquid-xenon dark matter experiment, and works on the detector-physics end: electron and single-photon backgrounds, calibration, and the characterisation of the anomalous low-energy events that currently limit sensitivity at the bottom of the energy spectrum. The programme is a pure exercise in pushing a detector's noise floor down until it is limited by irreducible physics (the neutrino fog). 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 — dark matter detection and NV-ensemble magnetometry are the same problem in different clothing — an exquisitely quiet detector, a signal below the background, and a systematics budget that determines everything — and the quantum-sensing community is increasingly supplying the readout technology (quantum-limited amplifiers, single-photon counters) that these experiments now need. Early-career PI.
O'Hare is a dark-matter phenomenologist whose work sits unusually close to instrumentation: he is the principal theorist of the 'neutrino fog' that limits direct-detection experiments, of directional dark matter detection (using the daily modulation of the WIMP wind to distinguish signal from background), and of the axion and ultralight dark-matter searches that increasingly rely on quantum sensors — haloscopes, comagnetometers, NMR-based searches and atomic magnetometers. He writes the sensitivity projections that tell experimentalists which quantum sensor to build. 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 axion/ALP search programme he works on consumes spin-ensemble magnetometry directly: CASPEr-class experiments are, in effect, precision NMR magnetometers operating far below pT/sqrt(Hz), and his phenomenology sets the sensitivity targets they aim at. Theory PI with strong experimental engagement.