The LKB atom interferometry group (also at SYRTE, Observatoire de Paris) develops cold atom inertial sensors including the world's best gyroscopes and gravimeters. Key research (Geiger, Landragin et al.): (1) interleaved cold atom gyroscope with 3.75 Hz sampling and 800ms interrogation (record sensitivity); (2) cold atom gradiometer for gravity gradient mapping; (3) atom chip-based compact sources for inertial navigation; (4) quantum optimal control for robust matter-wave sensing. QAFCA project (PEPR Quantique) on quantum sensors for geoscience and navigation. Note: The main PI is Remi Geiger (CNRS) / Arnaud Landragin, both at SYRTE/Observatoire de Paris (PSL), but LKB atom interferometry team is at ENS site.

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.

Michel Brune leads the Rydberg atoms / cavity QED group at LKB. Research: (1) circular Rydberg atoms trapped in high-finesse microwave cavities — quantum non-demolition measurement of photons, quantum state engineering; (2) fundamental quantum optics: decoherence, entanglement, quantum jumps, Schrödinger cat states; (3) quantum sensing of cavity fields with single atoms as probes. This group pioneered cavity QED experiments leading to the 2012 Nobel Prize (Haroche). Brune heads the laboratory.

Brune leads the Circular Rydberg Atom / Cavity QED group at LKB (Collège de France site), continuing the work of Serge Haroche (Nobel 2012). Note: Brune is employed by ENS, not Sorbonne Université; postdoc contracts are typically ENS/CNRS. Research directions: (1) Circular Rydberg atoms — atoms in extremely high principal quantum number states (n~50) with extremely long radiative lifetimes (~30 ms) and large dipole moments; (2) Cavity QED quantum sensing — single circular atoms probe the microwave field in a superconducting cavity photon-by-photon via quantum non-demolition measurement; (3) Quantum state engineering — generating Fock states, Schrödinger cat states, and entangled atom-field states in the cavity; (4) Tests of quantum complementarity — observing decoherence of mesoscopic superpositions in real time as a probe of quantum-to-classical transition. The 'quantum radio receiver' using single atoms to sense individual microwave photons is a landmark quantum sensing demonstration.

Clade works on atom-recoil interferometry, using Bloch-oscillation-enhanced light-pulse atom interferometers to measure the photon recoil velocity of atoms with extreme precision, from which the fine-structure constant is extracted as one of the most stringent tests of QED and the Standard Model. This precision-metrology approach is a core exemplar of atom-interferometric quantum sensing at LKB.

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.

Jean Dalibard's BEC group at LKB studies quantum gases, BEC, and strongly correlated quantum systems. Research: (1) 2D Bose gases and Berezinskii-Kosterlitz-Thouless transition; (2) gauge fields for neutral atoms — synthetic magnetism; (3) quantum simulation with ultracold atoms. Dalibard is a foundational figure in cold-atom physics; his group at LKB/Collège de France is relevant through quantum gas experiments tied to quantum simulation and precision measurement. Borderline case included given BEC foundations for sensing.

Deleglise works on cavity optomechanics and microwave-to-optical photon transduction, aiming to coherently interconnect superconducting-circuit and optical-photon quantum-network nodes; he is also affiliated with LPENS' Quantic team on circuit-QED and bosonic-code quantum error correction.