Ben Sauer

Mike Tarbutt

An ultracold fountain of YbF molecules for measuring the electron electric dipole moment

Laser-cooling is an incredibly powerful technique, with temperatures within a few millionths from absolute zero achievable in many atomic physics laboratories. The extension of such techniques to diatomic molecules is difficult because molecules have additional vibrational and rotational structure. There has long been great interest in producing and trapping cold molecules for applications including quantum simulation, quantum information and precision measurements. Direct laser cooling of molecules has only been demonstrated in the last few years.

In this project we aim to produce ultracold YbF molecules by direct laser cooling. These molecules are already used in an experiment to measure the shape of the electron, i.e. the electron’s electric dipole moment. This measurement tests theories of particle physics and it could be made orders of magnitude more precise by cooling the molecules to ultracold temperatures. Using four lasers, each with radio-frequency sidebands, YbF molecules can scatter tens of thousands of photons and thus be cooled to very low temperature. The project will implement this cooling scheme, investigate both Doppler and sub-Doppler cooling of the molecules, and aim to produce a fountain of ultracold molecules for measuring the electron electric dipole moment.