Deceleration and trapping of SrF molecules

TL;DR

This paper demonstrates the successful electrostatic deceleration and trapping of SrF molecules, achieving cold, slow molecular samples suitable for advanced physics experiments.

Contribution

It introduces a method to decelerate and trap heavy neutral molecules like SrF using a traveling-wave Stark decelerator, extending capabilities to heavier species.

Findings

Molecules are slowed from 190 m/s to rest and trapped for up to 50 ms.

Trapped molecules have a volume of 1 mm³ and a temperature of 60 mK.

Achieved a threefold increase in the mass of Stark-decelerated molecules.

Abstract

We report on the electrostatic trapping of neutral SrF molecules. The molecules are captured from a cryogenic buffer-gas beam source into the moving traps of a 4.5 m long traveling-wave Stark decelerator. The SrF molecules in $X^2\Sigma^+(v=0, N=1)$ state are brought to rest as the velocity of the moving traps is gradually reduced from 190 m/s to zero. The molecules are held for up to 50 ms in multiple electric traps of the decelerator. The trapped packets have a volume (FWHM) of 1 mm$^{3}$ and a velocity spread of 5(1) m/s which corresponds to a temperature of $60(20)$ mK. Our result demonstrates a factor 3 increase in the molecular mass that has been Stark-decelerated and trapped. Heavy molecules (mass$>$100 amu) offer a highly increased sensitivity to probe physics beyond the Standard Model. This work significantly extends the species of neutral molecules of which slow beams can be created for collision studies, precision measurement and trapping experiments.