Efficient associative ionization of ultracold lithium and the long-lived Li 2 +
N. Joshi, Vaibhav Mahendrakar, M. Niranjan +6 more
We report on the efficient production of Li 2 + ions in a magneto-optical trap (MOT) of Li atoms prepared in an ensemble of 2 S , 2 P , and 3 S states. A linear Paul trap surrounding the MOT is used to trap and investigate the time evolution of the ion populations. Associative ionization of Li( 2 P 3 / 2 ) and Li( 3 S 1 / 2 ) atoms, with a giant cross section of ∼ 2.2 × 10 6 a 0 2 , is the dominant Li 2 + production channel. Li 2 + decays to Li + via photodissociation and also in the absence of light, which are investigated experimentally and theoretically. A fraction of the Li 2 + ions are long-lived in the presence of the MOT light, implying that they are deeply bound and hence immune to dissociation, which opens up the possibility for studying Li 2 + molecular ion interactions with alkali atoms.
arXiv:2411.01209•Physical Review Research•Jun 10, 2026•0 citations