Accurate prediction and measurement of vibronic branching ratios for laser cooling linear polyatomic molecules

Chaoqun Zhang; Benjamin L Augenbraun; Zack D Lasner; Nathaniel B Vilas; John M Doyle; Lan Cheng

doi:10.1063/5.0063611

Accurate prediction and measurement of vibronic branching ratios for laser cooling linear polyatomic molecules

J Chem Phys. 2021 Sep 7;155(9):091101. doi: 10.1063/5.0063611.

Authors

Chaoqun Zhang¹, Benjamin L Augenbraun², Zack D Lasner², Nathaniel B Vilas², John M Doyle², Lan Cheng¹

Affiliations

¹ Department of Chemistry, The Johns Hopkins University, Baltimore, Maryland 21218, USA.
² Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA.

PMID: 34496585
DOI: 10.1063/5.0063611

Abstract

We report a generally applicable computational and experimental approach to determine vibronic branching ratios in linear polyatomic molecules to the 10^-5 level, including for nominally symmetry-forbidden transitions. These methods are demonstrated in CaOH and YbOH, showing approximately two orders of magnitude improved sensitivity compared with the previous state of the art. Knowledge of branching ratios at this level is needed for the successful deep laser cooling of a broad range of molecular species.