AlF, a Hot Candidate for New Physics with Ultracold Molecules
Researchers from the Fritz-Haber Institute of the Max-Planck Society in Berlin identified aluminum monofluoride (AlF) as an excellent molecule to be laser-cooled to ultra-low temperatures with a high density. Atoms have been laser-cooled with great success for over 30 years. Recently, this powerful technique has been extended to small molecules, but a major challenge remains: to increase the density of the laser-cooled molecular gas by many orders of magnitude. AlF has the potential to achieve this, and recent developments in laser technology now make it possible to use this molecule. AlF is stable and deeply-bound with unique properties, enabling cooling to very low temperatures and with a high density.
A dense and ultracold gas of polar molecules facilitates many new applications in fundamental science and technology. Precisely controlled molecules can be used to test fundamental models in physics, and to study new exotic phases of matter and chemistry at the quantum level. Arranged in a regular array, the molecules can serve as a model system for complex quantum systems that are too difficult to simulate on a computer, and as novel elements of a quantum information processor.
The researchers published highly accurate measurements of the detailed energy level structure of AlF in the electronic states relevant for laser cooling. Such accurate measurements can serve as an excellent benchmark for advanced quantum chemistry calculations and provide essential information for future cooling and trapping experiments.