An optical tweezer array of ultracold polyatomic molecules

Polyatomic molecules contain rich structures that make them enticing for a range of applications including quantum simulation and computation, quantum chemistry, controlled collisional studies, and precision searches for physics beyond the Standard Model. Optical tweezers are a desirable platform for many of these applications due to the ability to isolate many single molecules with arbitrary spatial arrangements and to individually control their quantum states. Here we report on the realization of an optical tweezer array of polyatomic molecules, CaOH, at ultracold temperatures (~100 μK). Starting from a MOT of CaOH, molecules are loaded into a 1064 nm optical dipole trap and then transferred into a 1D array of 780 nm optical tweezers. Due to the large number of excited states in CaOH, a tuned tweezer wavelength is used to optimize the imaging efficiency. This allows for nondestructive imaging of single molecules, with fidelities >90% for distinguishing loaded from empty traps. Finally, we report on initial experiments demonstrating coherent, single quantum state control of CaOH molecules in the tweezer array.