Barker leads the UCL Optomechanics Group, focusing on levitated nano/micro-oscillators in vacuum. Research directions: (1) Six-degree-of-freedom cooling — demonstrated simultaneous cavity cooling of all 6 DOF of a levitated nanoparticle (Nature Physics 2023, with Monteiro); (2) Sympathetic cooling of two nanoparticles via Coulomb interaction, squeezing transfer (Phys. Rev. Research 2023); (3) Dark matter searches — levitated nanoparticles as directional dark matter sensors sensitive to nuclear recoil and momentum transfer; QTFP-funded project 'Development of Levitated Quantum Optomechanical Sensors for Dark Matter Detection'; (4) Controlling mode orientations for directional force sensing near the quantum limit; (5) Quantum macroscopic superposition tests. Closely collaborates with Monteiro (theory), Bose (quantum entanglement tests), and Ghag (dark matter).
The Hosseini Lab (Quantum Atom Optics) investigates light–atom interactions in rare-earth crystals, room-temperature gases, and nanophotonic structures. Directions: (1) Quantum optical memories in Tm³⁺:YAG and Er³⁺-doped solids using atomic frequency comb (AFC) and gradient echo memory (GEM) protocols for telecom-wavelength quantum networking; demonstrated efficient storage of multi-dimensional telecom photons (Optica Quantum 2025, Phys. Rev. Appl. 2025); (2) Cooperative/collective light–matter interactions in periodic rare-earth ion arrays in nano/micro-photonic structures (collaboration with Oak Ridge NL, Aydin group) for enhanced quantum memory coherence; (3) Quantum squeezed light — applied to enhanced thermoreflectance sensing of electronic hotspots (Appl. Phys. Lett. 2024); (4) Coherent levitation of macroscopic sensors (DARPA YFA 2024, $500k): magnetic and optical trapping of mm-scale objects as high-Q oscillators for magnetometry, vibrational sensing, accelerometry, inertial, and force sensing. Lab actively seeking postdocs in integrated photonics, quantum memory, and levitation sensing (2024–2025). ASEE Curtis W. McGraw Research Award 2026.
Monteiro works on the theory and control of levitated optomechanical systems, including a stable 3D velocity feedback cooling scheme for independently controlling all three translational modes of an optically levitated nanoparticle with minimal cross-talk. Levitated optomechanics of this kind is being developed both as a force/impulse sensor of exquisite sensitivity and, in collaboration with UCL colleagues including Peter Barker, as a testbed for macroscopic quantum states relevant to proposed gravity-entanglement experiments.
Massimiliano Rossi's lab focuses on levitated systems, optical tweezers, and quantum measurement. Research: (1) optically levitated nanoparticles for force sensing and zeptonewton-scale measurements; (2) quantum measurement and control of levitated systems approaching the quantum ground state; (3) back-action-evading measurement schemes for levitated oscillators; (4) exploring quantum-to-classical transitions. The lab is developing levitated systems as sensors for dark matter and gravitational waves.
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.
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).