Observation of microwave shielding of ultracold molecules

Harnessing the potential wide-ranging quantum science applications of molecules will require control of their interactions. Here, we used microwave radiation to directly engineer and tune the interaction potentials between ultracold calcium monofluoride (CaF) molecules. By merging two optical tweezers, each containing a single molecule, we probed collisions in three dimensions. The correct combination of microwave frequency and power created an effective repulsive shield, which suppressed the inelastic loss rate by a factor of six, in agreement with theoretical calculations. The demonstrated microwave shielding shows a general route to the creation of long-lived, dense samples of ultracold polar molecules and evaporative cooling.

Automated summary

This study demonstrates the use of microwave radiation to engineer and control interaction potentials between ultracold calcium monofluoride molecules, resulting in an effective repulsive shield that suppresses inelastic loss rate by a factor of six. The findings provide a general route for creating long-lived, dense samples of ultracold polar molecules and implementing evaporative cooling techniques.