Matter near absolute zero has fascinating properties. Ultracold atoms and molecules can be confined in tiny regions of space and studied with great precision. At ZLab, we use laser light to create ultracold diatomic molecules of strontium. These molecules form a unique system that allows us to measure subtle yet important properties of basic molecular physics and chemistry. On a more fundamental level, the molecules provide an ensemble of tiny molecular clocks, where the molecule vibration determines the ticking rate. This type of quantum clock can help us test molecular quantum electrodynamics, the constancy of fundamental constants, and possible non-Newtonian forces at the nanometer scale.
Ultracold polar molecules have many applications from modeling strongly interacting quantum systems to producing exotic atomic gases via dissociation. At ZLab, we are exploring ways to directly cool molecules in order to manipulate and study them. We use a combination of buffer gas cooling and laser cooling with the goal of creating a magneto-optical trap for diatomic barium hydride (BaH) molecules. One exciting possibility is to precisely break the bond between the barium and hydrogen, leaving us with the ultracold fragments. Ultracold hydrogen would be the most fundamental atomic system which physicists can use to study a wide range of fundamental physics.
By attaining control over many properties of light and matter, we can design systems that reach new capabilities, both in fundamental and applied sciences. In collaboration with the Laboratory for Astrophysics, we built an apparatus to quantify a tiny contamination of a noble-gas detector used in Dark Matter searches. Together with the Department of Mechanical Engineering, we use microcavities to stabilize lasers for next-generation portable atomic clocks.