Hendrik Ulbricht's group pioneers levitated optomechanics and macroscopic quantum systems. Research: (1) optical levitation of nanoparticles for zeptonewton force sensing and quantum-to-classical transition tests; (2) magnetic levitation of micromagnets (diamagnetically stabilised) as ultralight dark matter detectors and magnetometers (fT/√Hz sensitivity demonstrated with LeMaMa levitated ferromagnet); (3) spin entanglement witness for quantum gravity (BMV experiment — levitated diamond with NV centre); (4) tests of the Diósi-Penrose model of wavefunction collapse. Multiple Reviews of Modern Physics; active in macroscopic quantum physics community.
Vanner leads the Quantum Measurement Lab, combining experiment and theory. Key research areas: (1) Cavity quantum optomechanics — developed a theoretical framework capturing nonlinear radiation-pressure beyond the linearised approximation, showing deterministic mechanical Wigner-negativity generation; demonstrated mechanical position-squared measurements in Nature Comms (2016); thermal noise squeezing by 36 dB (Nat. Comms 2013); (2) Brillouin-Mandelstam scattering — demonstrated strong coupling to high-frequency phonons (Optica 2019); single-phonon addition/subtraction via Brillouin (PRL 2021); quantum state tomography with non-Gaussianity; (3) Hybrid quantum systems — 'displacemon' architecture (nanobeam magnetically coupled to superconducting qubit, PRX 2018) for testing objective collapse and dark matter; (4) Quantum gravity tests — proposals for testing the generalised uncertainty principle (GUP) using optomechanical protocols. UKRI QTFP fellowship.
Verlot works on nano-optomechanics and quantum-limited displacement/force sensing with nanowire and levitated resonators, exploring ultrasensitive force detection and fundamental measurement limits. In the broader landscape of NV-centre ensemble quantum sensing (DEER, nano-NMR, T1 relaxometry) operating near pT/sqrt(Hz) sensitivity, this work is complemented by mechanical quantum sensors at the force-sensitivity frontier.
Vijayan leads the Quantum Engineering Lab at Manchester's Photon Science Institute, focusing on levitated optomechanics. Key results: (1) Programmable cavity-mediated long-range interactions between two levitated nanoparticles via coherently scattered photons (Nature Physics 2024, ETH Zurich/Innsbruck collaboration before Manchester); (2) Ground-state cooling of nanospheres and building toward quantum superpositions; (3) Quantum sensing with levitated systems — ultra-sensitive force/acceleration detectors; dark matter searches with nanoparticle momentum transfer detection (QTFP-funded collaboration with Darren Price); (4) Multi-particle quantum arrays. Royal Society University Research Fellow. Currently advertising PhD positions in quantum sensing with levitated optomechanical systems. Collaborates with Novotny (ETH), Romero-Isart (Innsbruck), and Millen (King's College London).
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.
Emil Zeuthen works on theoretical quantum optomechanics and quantum transduction. Research focuses on (1) figures of merit and protocols for quantum transducers (mechanical interfaces between microwave and optical domains); (2) back-action-evading measurements using optomechanical systems; (3) quantum limits for gravitational wave detection with mechanical systems in a negative-mass spin reference frame. Key QUANTOP theory collaborator bridging optomechanics and quantum sensing.