Laser-Cooled Polyatomic Molecules for Improved Electron Electric Dipole Moment Searches

TL;DR

This study demonstrates laser cooling of YbOH molecules, significantly reducing their temperature and increasing phase-space density, paving the way for high-precision electron EDM measurements and probing physics beyond the Standard Model.

Contribution

The paper develops a comprehensive numerical model of laser cooling for YbOH and achieves significant cooling improvements, enabling future high-sensitivity EDM searches.

Findings

Achieved Doppler and Sisyphus cooling of YbOH molecules.

Reduced transverse temperature to below 600 μK.

Projected feasibility of laser cooling and trapping for high-sensitivity EDM experiments.

Abstract

Doppler and Sisyphus cooling of $^{174}$YbOH are achieved and studied. This polyatomic molecule has high sensitivity to physics beyond the Standard Model and represents a new class of species for future high-precision probes of new T-violating physics. The transverse temperature of the YbOH beam is reduced by nearly two orders of magnitude to $< 600 \, \mu$K and the phase-space density is increased by a factor of $>6$ via Sisyphus cooling. We develop a full numerical model of the laser cooling of YbOH and find excellent agreement with the data. We project that laser cooling and magneto-optical trapping of long-lived samples of YbOH molecules are within reach and these will allow a high sensitivity probe of the electric dipole moment (EDM) of the electron. The approach demonstrated here is easily generalized to other isotopologues of YbOH that have enhanced sensitivity to other symmetry-violating electromagnetic moments.