Novel Laser-Coolable Molecular Species

Laser cooling techniques have recently been extended to diatomic and polyatomic molecules. The molecules that have so far been laser cooled are highly symmetric, linear molecules. Previous cooling schemes have relied crucially on these high symmetry states. Here, we identify several new classes of laser-coolable molecules with complex molecular and electronic structure. Among these are non-linear symmetric top molecules like CaOCH$_3$ [1], asymmetric rotors including CaSH and CaNH$_2$ [2], and exotic molecules with multiple optical cycling centers, such as CaCCSr [3]. We discuss ongoing experimental and theoretical work, including dispersed fluorescence spectroscopy, demonstrations of optical photon cycling, and structural calculations. The addition of such species to the laser-cooled molecular toolbox will lend itself to diverse applications ranging from quantum computing and simulation to quantum chemistry to precision measurements and fundamental physics. [1] Yu et. al., New J. Phys. 21, 093049 (2019). [2] Augenbraun et. al., arXiv:2001.11020 (2020). [3] Ivanov et. al., J. Phys. Chem. Lett. (2020).