Progress Towards a 3D Magneto-Optical Trap of AlCl

Ultracold molecules are emerging as versatile platforms for precision measurement, quantum‑state–resolved chemistry, and quantum technologies. Achieving the scalability recently demonstrated with ultracold atoms—such as in‑situ qubit replenishment and thousand‑site occupied tweezer arrays—will require rapidly producing large, dense ultracold molecular samples, and direct laser cooling and trapping offers a promising route. Aluminum monochloride (AlCl) combines favorable vibrational branching with an alkaline‑earth–like electronic structure that supports both strong cycling transitions for trap loading and narrow transitions suitable for deep laser cooling and coherent control. Here we will present an experimental update including our latest progress toward realizing a 3D magneto‑optical trap of AlCl molecules.