Description: Coupling of qubits or spins to microwave resonators for readout and quantum control.
Pioneer in spintronics and quantum information engineering. Research spans: (1) NV-center spin qubits in diamond for quantum sensing and communication including nanomagnetic imaging; (2) spin defects in SiC and Er-doped hosts for quantum network nodes at telecom wavelengths; (3) molecular and protein-based spin qubits (2025 fluorescent-protein spin qubit, Physics World Top-10); (4) coherent Er spin defects in colloidal nanocrystal hosts (2024, with Alivisatos). Founding Director Chicago Quantum Exchange. Joint Senior Scientist Argonne. Large infrastructure-rich group with strong industry ties (IBM, Intel, Google quantum).
Bartholomew trained with Sellars (ANU) and Faraon (Caltech) and runs the Quantum Integration Laboratory, which works on rare-earth ions (erbium, europium, ytterbium) in crystals and in nanophotonic devices. Rare-earth ions have the longest optical and spin coherence times of any solid-state emitter, which makes them simultaneously the best optical quantum memories and, less obviously, extremely good sensors: the group works on rare-earth-based microwave and RF quantum sensing, on-chip integration of ions with photonic and superconducting circuits, and telecom-band spin-photon interfaces. Positioned against the established body of NV-ensemble quantum sensing work β DEER, nanoscale NMR and T1 relaxometry protocols operating at pT/sqrt(Hz) field sensitivity β rare-earth ensembles are the closest solid-state analogue to NV ensembles, with narrower optical lines and longer coherence but cryogenic operation; protocols like DEER and dynamical-decoupling-enhanced sensing at pT/sqrt(Hz) map across directly. This is one of the best fits at Sydney for a solid-state spin-sensing candidate.
BΓΈttcher builds hybrid superconductor-semiconductor (Al/InAs) devices and develops new circuit-QED-based quantum sensing tools to probe emergent phases -- unconventional pairing, topological superconductivity -- in 2D and mesoscopic quantum materials that are difficult to access with conventional transport measurements.
Breeze is a senior research fellow at UCL working on room-temperature solid-state masers. Research directions: (1) Pentacene maser β first demonstration of a room-temperature, continuous-wave solid-state maser (Science 2018) using photoexcited triplet-state pentacene in p-terphenyl crystal; achieving amplification with noise temperature near 1 K; (2) Diamond NV maser β developing NV-center-based maser for ultra-low-noise microwave amplification at room temperature, relevant to quantum sensing readout chains; (3) Maser applications β quantum-limited amplification for dark matter searches, MRI signal amplification, and quantum communication repeaters; (4) Spin dynamics β understanding triplet-state dynamics in organic crystals for spin polarization control. Strong relevance to quantum-limited microwave sensing.
Cassidy (formerly Microsoft/Sydney) builds hybrid superconductor-semiconductor quantum devices and the microwave measurement chains needed to read them out: dispersive gate sensing, superconducting resonators coupled to semiconductor nanostructures, and quantum-limited parametric amplification. The programme sits at the boundary between quantum computing hardware and quantum sensing β many of the same circuits used to read a qubit are, viewed differently, near-quantum-limited detectors of microwave photons or of charge. Positioned against the established body of NV-ensemble quantum sensing work β DEER, nanoscale NMR and T1 relaxometry protocols operating at pT/sqrt(Hz) field sensitivity β a superconducting-resonator readout chain with a quantum-limited amplifier is the leading route to inductively-detected spin resonance at sensitivities well below the pT/sqrt(Hz) regime accessible to optical NV ensembles, and Cassidy's group has the full stack of skills required. Mid-career, actively building; good autonomy for a postdoc.
Develops quantum metrology for ultra-weakly-coupled dark sectors and fundamental physics. Directions: (1) axion dark matter detection using entangled probe state preparation and superconducting qubit QND readout (HAYSTAC, ADMX); (2) dark radiation/energy detection with Cooper-pair box quasiparticle sensors; (3) GW detectors based on high-B-field microwave cavities probing early-universe phase transitions; (4) emergent gauge symmetries in quantum spin liquids. Co-PI DARPA QuSeN (quantum sensing of neutrinos, 2025). Devices/Sensors lead, DOE Quantum Science Center.
Chu leads the Hybrid Quantum Systems Group coupling mechanical resonators to superconducting circuits and diamond color centers. Research directions: (1) Circuit quantum acousto-dynamics (cQAD) β HBAR resonators coupled to transmon qubits achieve single-phonon nonlinearity (coherence/anharmonicity ratio 6.8), mechanical qubit gates demonstrated (arXiv 2406.07360, 2024); (2) Optimal control for high Fock state preparation in bulk resonators; (3) Ultra-cold mechanical quantum sensor β cryogenically cooled nanomechanical oscillators as probes for new physics beyond the standard model; (4) Coupling NV/SiV color centers in diamond to acoustic waves for hybrid quantum memory and transduction. Targets long-lived phonon storage for quantum networking and quantum sensing beyond the standard quantum limit.
Specializes in quantum information and hybrid quantum systems. Directions: (1) superconducting qubit quantum computing and error correction; (2) hybrid quantum systems coupling superconducting qubits to mechanical resonators, spin systems, and optical photons; (3) quantum-limited microwave amplification; (4) co-PI DARPA QuSeN β quantum sensing of neutrinos via phonon-coupled SC qubit sensors (2025). Director Pritzker Nanofabrication Facility (PNF). AAAS and APS Fellow.
Theorist developing frameworks for quantum sensing, control, and amplification in driven-dissipative quantum systems. Directions: (1) quantum noise theory for optomechanical and electromechanical sensors β fundamental limits and backaction evasion; (2) parametric amplification and squeezing beyond standard quantum limit; (3) non-reciprocal quantum systems for quantum-limited amplifiers; (4) quantum sensing theory for GW detectors and CMB experiments. 2020 Simons Investigator in Theoretical Physics.
Cohadon and Heidmann co-lead the Optomechanics and Quantum Measurements group at LKB. Research directions: (1) Back-action evasion and Standard Quantum Limit (SQL) β early demonstration of radiation-pressure back-action in a micro-mirror (Nature 2006), subsequent beating of SQL via quantum correlations; (2) Micro/nanomechanical resonators β 2D photonic crystal deformable slabs, membrane-in-the-middle cavities, micropillar resonators for radiation-pressure optomechanics; (3) Superconducting qubitβmacroscopic membrane coupling β Jacqmin & DelΓ©glise team: resonant coupling of transmon qubit to MHz membrane oscillator, tracking quantum motion with 300 repeated interactions (2025); high-impedance hyperinductors for electromechanics; (4) Gravitational wave detector contributions β VIRGO/LIGO data analysis and quantum noise modeling. Applications include back-action-evading force sensing and tests of quantum mechanics at macroscopic scales.