An ultracold molecular beam for testing fundamental physics

TL;DR

This paper demonstrates a method to produce an ultracold YbF molecular beam using laser cooling, significantly enhancing brightness and temperature control, with implications for precision fundamental physics experiments.

Contribution

The study introduces a two-dimensional transverse laser cooling technique for YbF molecules, achieving ultracold temperatures and increased beam brightness for fundamental physics tests.

Findings

Ultracold YbF beam with over 200,000 molecules per shot.

Temperature below 200 μK achieved.

300-fold increase in beam brightness.

Abstract

We use two-dimensional transverse laser cooling to produce an ultracold beam of YbF molecules. Through experiments and numerical simulations, we study how the cooling is influenced by the polarization configuration, laser intensity, laser detuning and applied magnetic field. The ultracold part of the beam contains more than $2 \times 10^5$ molecules per shot and has a temperature below 200 $\mu$K, and the cooling yields a 300-fold increase in the brightness of the beam. The method can improve the precision of experiments that use molecules to test fundamental physics. In particular, the beam is suitable for measuring the electron electric dipole moment with a statistical precision better than $10^{-30}$ e cm.