Combes is a theorist of continuous quantum measurement, quantum trajectories, quantum-limited amplification and quantum filtering, with a strong record of working directly alongside superconducting-circuit and optical experiments rather than in isolation. Recent directions include the fundamental limits of amplifier-based sensing, error-corrected and adaptive metrology protocols, and characterisation/verification of noisy quantum devices. 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 work supplies the estimation-theoretic scaffolding — quantum Fisher information, back-action limits, adaptive protocols — that determines whether an NV ensemble running DEER or nanoscale NMR at pT/sqrt(Hz) is actually operating at its fundamental bound or leaving sensitivity on the table. Theory PI, but explicitly experiment-facing.
Reilly's Quantum Nanoscience Laboratory works on the interface between quantum devices and the classical control hardware needed to run them at scale — custom VLSI CMOS operating below 100 mK, high-bandwidth dispersive readout, and cryogenic microwave engineering — a programme built up during his long association with Microsoft's quantum effort. A distinct and directly relevant second thread is the manipulation of spin states in nanoparticles for new imaging modalities in medicine: hyperpolarisation and spin-state engineering of nanoparticle contrast agents, which is quantum control applied to MRI. 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 cryo-CMOS readout chain he builds is exactly the enabling technology that would let a pT/sqrt(Hz) spin-ensemble sensor be multiplexed into an array rather than run one channel at a time; and the nanoparticle-MRI thread is an independent route into biological spin sensing. Large group, strong engineering culture, significant industry entanglement.
A pioneer of circuit quantum electrodynamics, Schuster's group uses superconducting qubits and microwave resonators both as quantum-information platforms and as ultra-sensitive quantum-limited sensors/spectrometers, extending qubit-based readout to precision spectroscopy of otherwise inaccessible microwave-frequency phenomena.
Xu leads the Experimental Quantum Engineering group with a joint ETH–PSI appointment. Research directions: (1) Superconducting circuit quantum sensing — using qubits-as-sensors for detecting weak microwave signals beyond standard quantum limits, quantum non-demolition readout of photon fields; (2) Quantum error correction enabled sensing — integrating bosonic codes (cat qubits, binomial codes) into sensing protocols; (3) Quantum acoustics — coupling superconducting qubits to surface acoustic wave (SAW) resonators for hybrid quantum sensing; (4) Novel quantum hardware at PSI — leveraging PSI's infrastructure for cryogenic device fabrication and testing. Connected to the ETH–PSI Quantum Computing Hub.