NSF-BSF: Elucidating Interactions between Multiple Optical Cycling Centers in Hypermetallic Polyatomic Molecules

Smithsonian Institution Astrophysical Observatory, Cambridge MA

Investigators

Abstract

Laser-cooled molecules are a powerful tool for exploring the frontiers of quantum science and ultracold physics, provided their energy can be cooled in all degrees of freedom to temperatures very close to absolute zero. Although certain classes of molecules can be cooled with precisely engineered laser-light, particularly those containing a single heavy atom, extending efficient laser cooling to molecules more generally has proven challenging. This project aims to understand the general design principles that affect the performance of exotic, new classes of laser-coolable molecules containing multiple heavy atoms. Through a collaborative National Science Foundation - US Israel Binational Science Foundation experimental program, the investigators will explore how light from radio to visible wavelengths interacts with such molecules. This effort will broaden the diversity of cold molecule applications spanning quantum computing and simulation to tabletop searches for new physics. Such cutting-edge yet fundamental measurements are well suited to educating and training students in STEM fields, and such mentorship is a core project aim. All demonstrations of direct laser-cooling to date have used molecules containing a single heavy-atom photon-cycling center. More complex species containing multiple optical centers have the potential to greatly increase the versatility of laser-cooled molecules, but have not been thoroughly explored experimentally. This program comprises a systematic spectroscopic study of substituted hydrocarbons, including acetylene chains and benzene rings, containing multiple alkaline earth or alkaline-earth-like atoms. By combining broadband optical and microwave data, the investigators will directly probe how the intricacies of electronic structure and chemical bonding influence the molecular properties relevant to laser-cooling applications, as well as the molecular physics of these exotic, biradical species in general. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.