Description: Fabrication of transition edge sensors and phonon-mediated cryogenic particle detectors for dark matter and neutrino experiments.
Prof. Figueroa-Feliciano leads Northwestern's experimental program in quantum sensing for particle physics. Key directions: (1) SuperCDMS SNOLAB — Northwestern's NU's role in the Super Cryogenic Dark Matter Search at SNOLAB (2 km underground in Canada), using ultra-pure Si and Ge crystals with superconducting TES sensors to detect low-mass dark matter (particles below the proton mass); in March 2026 the experiment reached operating temperature (<10 mK), transitioning to detector calibration for the first ever dark matter search at the site; (2) NEXUS facility at Fermilab: Northwestern-built test facility led by Figueroa-Feliciano for SuperCDMS detector calibration and for measuring how ionizing radiation affects superconducting qubits (published fall 2025); (3) Qubit-based quantum sensing: developing HVeV R&D devices with <1 eV resolution and qubit parity-detection techniques for eV-scale and sub-eV dark matter detection. Associate Vice President for Research at Northwestern; INQUIRE Executive Committee. Joint appointment at Fermilab.
Jian-Rong Gao develops superconducting THz heterodyne detector arrays for radio astronomy and fundamental physics applications. Key work: (1) hot electron bolometer (HEB) and SIS mixer THz receivers operating at sub-mm and THz frequencies; (2) detector arrays for space and ground-based radio telescopes (Herschel, ALMA, and future missions); (3) low-noise amplification at THz frequencies. Joint professor TU Delft and SRON (Netherlands Institute for Space Research).
Jones leads the SPIDER balloon-borne CMB polarimeter (and the successor Taurus mission), building and flying large TES bolometer arrays from Antarctic long-duration balloon platforms to measure degree-scale CMB polarization with minimal atmospheric loading, and also leads SuperBIT, a near-diffraction-limited stratospheric optical telescope. Like Staggs, he is included here as an astronomy/instrumentation pivot whose science case rests on cutting-edge cryogenic detector-array sensitivity.
McCallum works on the materials and detector physics of donor qubits in silicon and colour centres in diamond and silicon carbide: defect engineering by ion implantation and annealing, characterisation of the resulting spin coherence, and — most relevant to a sensing postdoc — the development of superconducting and semiconductor detectors capable of registering single implanted ions with near-unit efficiency, which is what turns implantation from a statistical process into a deterministic one. He also works on near-surface colour centres, where surface termination and Fermi-level control set the achievable coherence. 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 — his group supplies the near-surface, coherence-optimised spin ensembles that DEER, nanoscale NMR and T1-relaxometry protocols at pT/sqrt(Hz) sensitivity actually depend on.
Staggs is PI of the Atacama Cosmology Telescope (Advanced ACTPol) and co-Director of the Simons Observatory, leading development and production of very large, sensitive cryogenic transition-edge-sensor (TES) focal-plane detector arrays used to map cosmic microwave background temperature and polarization anisotropies at ever finer angular resolution. This is included as an astronomy pivot on the strength of its quantum-limited cryogenic detector instrumentation, which is the enabling technology for the high spectral/spatial resolution CMB science.