Briant works in LKB's optomechanics and quantum-measurement team, using high-finesse Fabry-Perot cavities coupled to mirror/membrane mechanical resonators to study radiation-pressure back-action, quantum noise, and force sensing near the standard quantum limit, alongside Pierre-Francois Cohadon and Antoine Heidmann.
Cohadon and Heidmann co-lead the Optomechanics and Quantum Measurements group at LKB. Research directions: (1) Back-action evasion and Standard Quantum Limit (SQL) — early demonstration of radiation-pressure back-action in a micro-mirror (Nature 2006), subsequent beating of SQL via quantum correlations; (2) Micro/nanomechanical resonators — 2D photonic crystal deformable slabs, membrane-in-the-middle cavities, micropillar resonators for radiation-pressure optomechanics; (3) Superconducting qubit–macroscopic membrane coupling — Jacqmin & Deléglise 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 — VIRGO/LIGO data analysis and quantum noise modeling. Applications include back-action-evading force sensing and tests of quantum mechanics at macroscopic scales.
Pierre-François 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 — 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.
Courty provides theoretical support to LKB's optomechanics and quantum-measurement experiments, working on quantum-noise theory for radiation-pressure coupled cavities and standard-quantum-limit-evading measurement schemes.
Guerlin works on quantum-limited optomechanical measurement and quantum non-demolition detection schemes within LKB's optomechanics team, building on cavity-QED-style quantum-measurement concepts applied to mechanical degrees of freedom.
Heidmann is a founding member of LKB's cavity-optomechanics group, whose work on radiation-pressure effects, ponderomotive squeezing, and quantum-limited displacement/force measurement underpins the lab's broader precision-metrology and gravitational-wave-adjacent quantum-optics programme.
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.