Testing Fundamental Physics with laser-cooled Molecules

Testing fundamental physics with laser-cooled molecules

Over the last decade, there has been rapid progress in laser cooling and trapping of polar molecules. This progress has been driven by the many exciting applications of ultracold molecules. They can be used to study many-body quantum physics, process quantum information and improve our understanding of chemical processes at the quantum level. They can also be used to test physics beyond the Standard Model [1].

In this talk, I will first introduce our methods for cooling and trapping polar molecules, then describe how we use these ultracold molecules to probe fundamental physics. In one experiment, we are developing a molecular lattice clock based on ultracold CaF molecules and using it to test the hypothesis that the fundamental constants may vary in time. Our clock will be especially sensitive to variations of the electron-to-proton mass ratio [2]. In a second experiment, we aim to use ultracold YbF molecules to measure the electron’s electric dipole moment (EDM) with precision beyond the current state of the art [3]. The measurement is a test of time-reversal symmetry violation and an extremely sensitive probe of new physics, including models of supersymmetry. I will present the status of these experiments and our plans for future developments.

[1] DeMille D, Hutzler N R, Rey A M and Zelevinsky T 2024 Nature Physics 20, 741

[2] Barontini G et al. 2022 EPJ Quantum Technol. 9, 12

[3] Roussy T S et al. 2023 Science 381, 46

[4] Jenkins R A et al. 2026 arXiv:2602.00713