Caldwell is a Royal Society University Research Fellow establishing the Molecular Quantum Matter Lab at UCL. Research directions: (1) Precision molecular spectroscopy for dark matter and fifth-force searches — measuring isotope shifts in molecular systems to test Standard Model predictions and probe new forces between neutrons and electrons; (2) Quantum control of molecules in external fields — laser cooling, Stark deceleration, and magneto-optical trapping of polar molecules; (3) Molecular beam spectroscopy with frequency comb referencing for ultra-high-precision lineshape measurements. The lab aims to build the most precise molecular spectrometer for BSM physics searches. Actively building the lab and seeking motivated students/postdocs.

Merkt leads the Molecular Physics and Spectroscopy group at ETH D-CHAB. Research directions: (1) High-resolution XUV/VUV spectroscopy — using synchrotron radiation and table-top laser sources to study molecular Rydberg states, ionization thresholds, and ro-vibrational structure at sub-MHz precision; (2) Precision molecular clock transitions — proposing and measuring molecular transitions suitable for fundamental constant variation searches (μ, α); (3) Metastable atom and ion trapping — developing new trapping methods for precision spectroscopy of exotic species; (4) Pulse and Fourier transform microwave spectroscopy — rotational spectroscopy of transient species. Direct applications to molecular quantum sensing and fundamental physics.