Trapping cold hydrogen molecules

Due to its simplicity, H2 constitutes a perfect tool for testing fundamental physics: testing quantum electrodynamics, determining fundamental constants, or searching for new physics beyond the Standard Model. H2 has a huge advantage over the other simple calculable systems of having a set of a few hundred ultralong living rovibrational states, which implies the ultimate limit for testing fundamental physics with H2 at a relative accuracy level of 10^-24. The present experiments are far from this limit. I will present our so far results of an ongoing project aimed at trapping cold H2. We develop an ultra-strong optical dipole trap. The time-dependent potential is going to recapture the coldest fraction of the cryogenic H2 cloud. We develop a new type of cryogenic effusive valve to prepare a cryogenic H2 sample. I will also discuss our preliminary results obtained with cryogenic cavity [1] and our recent results on 1D-trapping spectroscopy of H2 obtained in the labs of Wim Ubachs in Amsterdam [2].

[1] K. Stankiewicz, et al., Cavity-enhanced spectroscopy in the deep cryogenic regime for quantum sensing and metrology, Nature Physics (2026), DOI: 10.1038/s41567-026-03204-8
[2] W. Ubachs, F. M. J. Cozjin, M. L. Diouf, C. Lauzin, H. Jóźwiak and P. Wcisło
Letokhov-Chebotayev Intracavity Trapping Spectroscopy of H2. Physical Review Letters 135, 223201 (2025), DOI: 10.1103/rxcj-6dw6