Tags - (5) quantum non-demolition measurement

Department(s)/lab(s): School of Physics | Combes Quantum Measurement Theory Group @ UMelb
Summary:

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 β€” DEER, nanoscale NMR and T1 relaxometry protocols operating at pT/sqrt(Hz) field sensitivity β€” his work supplies the estimation-theoretic scaffolding β€” quantum Fisher information, back-action limits, adaptive protocols β€” 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.

Department(s)/lab(s): School of Physics | Quantum Theory Group @ USyd
Summary:

Doherty is a theorist whose early work established much of the modern framework for continuous quantum measurement and quantum feedback control, and who now works across quantum information theory, error correction and the characterisation of quantum devices. For a sensing candidate the relevant body of work is the measurement/feedback theory: conditional evolution under continuous observation, the role of back-action, and the design of feedback protocols that stabilise a quantum system while extracting information from it. 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€” the continuous-measurement formalism he helped build is what one uses to ask whether a pT/sqrt(Hz) NV ensemble measurement is saturating its quantum Fisher information bound or merely its shot-noise bound. Borderline inclusion β€” the current group output is largely quantum computing theory rather than sensing β€” but retained under the inclusive rubric given the measurement-theory pedigree.

Department(s)/lab(s): Physics | LKB - Rydberg Atoms Team @ CNRS
Summary:

Gleyzes is a CNRS researcher in the Rydberg Atoms team at LKB (successor to Serge Haroche's cavity-QED group), where he achieved the first quantum non-demolition detection of a single microwave photon. The team now prepares non-classical states of circular Rydberg atoms as probes for electric- and magnetic-field sensing below the standard quantum limit, uses quantum optimal control to navigate large Rydberg Hilbert spaces, and has demonstrated millisecond-lived circular states at room temperature, a route toward practical Rydberg-atom quantum sensors and simulators.

Department(s)/lab(s): Physics and Electrical Engineering & Computer Sciences | Murch Lab @ UCB
Summary:

Murch studies continuous quantum measurement and feedback control in superconducting circuit QED systems, including some of the earliest experiments resolving quantum backaction and weak-value amplification, work directly relevant to the quantum limits of continuous sensing and metrology.

Department(s)/lab(s): School of Physics | Quantum Control Laboratory @ USyd
Summary:

Wolf works on trapped-ion quantum sensing, using the motional degrees of freedom of single ions and small crystals as transducers for weak electric fields and forces, together with non-classical motional states (squeezed and Fock states) to enhance the achievable sensitivity. The broader agenda is to use trapped ions as a testbed for fundamental measurement limits β€” quantum-enhanced amplification of small displacements, quantum non-demolition readout of motion β€” with an eye to applications in electric-field metrology and searches for new physics. 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€” trapped-ion motional sensing is the cleanest available platform for demonstrating the entanglement-enhanced scaling that NV ensembles at pT/sqrt(Hz) approach only in the shot-noise-limited regime. Early-career independent PI within the Quantum Control Laboratory; smaller group, higher autonomy.