Description: Josephson parametric amplifiers and SQUIDs operating at or below the standard quantum limit.
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 superconducting detector and readout systems for CMB observations. Directions: (1) SQUID-multiplexed readout architecture for large TES bolometer arrays (SPT-3G, CMB-S4); (2) transition-edge sensor bolometer fabrication and characterization; (3) MKID detector development; (4) CMB-S4 instrument design. Argonne joint appointment. Deep expertise in quantum-limited cryogenic detector readout.
Chaudhuri leads the Princeton Axion Search (PXS) and is a core contributor to the DMRadio program, using solenoidal lumped-element LC resonators, DC-SQUID and near-quantum-limited (traveling-wave parametric amplifier) readout to search for QCD axion dark matter from roughly neV to ueV masses; his group explicitly frames this as electromagnetic quantum sensing beyond the Standard Quantum Limit. He is actively developing superconducting resonators and RF quantum upconverters that push readout sensitivity toward and below the SQL.
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.
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.
Pierre-FranΓ§ois Cohadon leads the optomechanics and quantum measurements group at LKB (ENS site). Research: (1) mechanical quantum systems and back-action-evading measurement; (2) gravitational wave detector enhancement β white-light cavity proposals to extend GW sensitivity; (3) quantum optomechanical sensing of forces and fields. The group was key to the LKB optomechanics tradition and is affiliated with Virgo/LIGO enhancement proposals.
Croot returned from Princeton to found Sydney's Superconducting Quantum Circuits Laboratory. The programme uses superconducting circuits both as quantum processors and as extremely sensitive probes: coupling microwave resonators and qubits to other degrees of freedom (mechanical modes, semiconductor structures, spins) to build hybrid systems, and developing the quantum-limited amplification chain that makes single-microwave-photon detection possible. 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 superconducting circuits are the principal competitor technology for detecting the weak microwave signals that NV ensembles read magnetically; a quantum-limited or squeezed microwave amplifier is what lets an inductively-detected spin ensemble reach β and beat β the pT/sqrt(Hz) regime. Newly established, well-equipped lab; high autonomy for a postdoc and active recruitment as the lab builds out.
Quantum information theorist with strong focus on quantum sensing. Directions: (1) error-correction-enhanced quantum sensing protocols surpassing Heisenberg limit; (2) quantum transduction theory for microwave-optical interfaces; (3) global-scale quantum network architecture; (4) room-temperature NV-based nanoscale magnetometry theory; (5) sub-wavelength quantum imaging protocols. Works closely with experimental quantum sensing groups at UChicago and beyond.
Kamal directs the QUEST (QUantum Engineering Science and Technology) group, developing theory for quantum-limited readout of superconducting circuits: nonreciprocal parametric (Josephson-junction) amplifiers, left-handed-metamaterial traveling-wave amplifiers, and autonomous entanglement stabilization/error-correction protocols. Her work sets the fundamental noise limits that superconducting-qubit-based quantum sensors and quantum computers can approach, in close collaboration with experimental groups at NIST Boulder and elsewhere. The group is actively recruiting postdoctoral scholars.
Experimental cosmologist developing next-generation CMB detector arrays. Directions: (1) CMB-S4 detector development β leading TES bolometer and MKID array design for 500,000-detector focal plane; (2) South Pole Telescope SPT-3G operations and analysis; (3) cryogenic readout electronics including SQUID multiplexing at millikelvin temperatures; (4) quantum-limited photon detection at mm/submm wavelengths. APS Fellow.