Experimental AMO physicist using ultracold atoms and optical lattices for quantum simulation and sensing. Directions: (1) Efimov and few-body physics in ultracold Cs and Cs-Li mixtures; (2) quantum phase transitions and strongly correlated quantum matter in optical lattices; (3) optical tweezer arrays for single-atom and single-molecule quantum simulation. Develops novel imaging techniques for in-situ atomic density measurements.
Choi builds large-scale, individually addressable arrays of solid-state spin qubits (NV centers and related defects) and entangles ancilla nuclear/electronic spins to demonstrate high-precision, entanglement-enhanced quantum sensing, extending the ensemble NV magnetometry regime (DEER/T1 protocols at pT/√Hz) toward single- and few-spin sensors with quantum-error-corrected readout.
PREFERRED. Choi is a theorist working at the intersection of quantum information science and out-of-equilibrium many-body dynamics, and with experimental collaborators (Lukin group) he developed quantum-logic-enhanced protocols that let dense, interacting NV ensembles surpass the interaction-limited sensitivity bound for AC magnetometry. This directly extends the lineage of NV ensemble quantum sensing experiments (DEER, nanoscale NMR, T1 relaxometry) that have driven ensemble magnetometers toward pT/sqrt(Hz) sensitivities, by using engineered many-body Hamiltonians and quantum control rather than dilution alone.
Develops quantum metrology for ultra-weakly-coupled dark sectors and fundamental physics. Directions: (1) axion dark matter detection using entangled probe state preparation and superconducting qubit QND readout (HAYSTAC, ADMX); (2) dark radiation/energy detection with Cooper-pair box quasiparticle sensors; (3) GW detectors based on high-B-field microwave cavities probing early-universe phase transitions; (4) emergent gauge symmetries in quantum spin liquids. Co-PI DARPA QuSeN (quantum sensing of neutrinos, 2025). Devices/Sensors lead, DOE Quantum Science Center.
Develops quantum sensors based on neutral atoms and solid-state atom-like defects (e.g. NV diamond) for measuring inertial forces, magnetic fields, and time, and applies nanophotonics/nanofabrication to improve the size, weight, and performance of quantum sensing instruments; collaborates with Mikhail Kats on metasurface-enhanced atomic magnetometers.
Nobel laureate Steven Chu's group spans laser cooling/trapping of atoms and single-molecule biophysics, using optical and magnetic tweezers and single-molecule fluorescence to study DNA/RNA folding, molecular motors, and signal transduction -- one of the earliest applications of AMO-derived single-particle measurement precision to living systems.
Chu leads the Hybrid Quantum Systems Group coupling mechanical resonators to superconducting circuits and diamond color centers. Research directions: (1) Circuit quantum acousto-dynamics (cQAD) — HBAR resonators coupled to transmon qubits achieve single-phonon nonlinearity (coherence/anharmonicity ratio 6.8), mechanical qubit gates demonstrated (arXiv 2406.07360, 2024); (2) Optimal control for high Fock state preparation in bulk resonators; (3) Ultra-cold mechanical quantum sensor — cryogenically cooled nanomechanical oscillators as probes for new physics beyond the standard model; (4) Coupling NV/SiV color centers in diamond to acoustic waves for hybrid quantum memory and transduction. Targets long-lived phonon storage for quantum networking and quantum sensing beyond the standard quantum limit.
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.
Alex Clark's group works at the interface of quantum science and technology, focusing on: (1) quantum imaging with undetected photons (mid-IR sensing at 3.28 µm using CMOS cameras and entangled photons — QIUP technique); (2) single-molecule photon sources (molecules coupled to nanophotonic cavities); (3) quantum memory protocols (ORCA and ATS in atomic vapours for telecom-band photon storage); (4) integrated photonics for quantum sensing. Director of QET Labs; Work Package Leader in three UK Quantum Technology Hubs.
Rachel Clark's research focuses on integrated quantum photonic devices, squeezed light generation on-chip, and nonlinear photonics. Research: (1) on-chip squeezed light generation in silicon nitride and lithium niobate waveguide platforms; (2) continuous-variable quantum photonic circuits; (3) nonlinear photonics for quantum sensing. This group is directly relevant to quantum-enhanced sensing with squeezed light.