Different Classes of Triatomic Molecules in Ultracold environment

The study of ultracold collisions of neutral atoms and molecules provides a valuable environment to observe quantum effects at very low temperatures, which has garnered much attention due to recent experimental advancements in cooling and trapping these species. In this survey, we examine two different classes of ultracold trimers. The first class is a long-range triatomic molecule formed by the collision of a ground state atom (S) and a ground state dimer, with the absorption of a photon at a frequency red-detuned from the atomic resonance line [endif]-->. The laser frequency can be detuned to different vibrational trimer states [1,2]. The second class of interest is the ultra-long-range molecules (ULRMs), created when a highly excited Rydberg electron collides with two ground state atoms. This results in various triatomic molecular states with different geometries, including separable potential energy in the case of an S electronic state. However, this separability breaks down in the case of a [endif]--> electronic state due to the degeneracy of the [endif]--> manifold. We explore these different types of molecular states in Rb (n=15) hydrogenic manifold.



[1] Perez-Rios, J.; Lepers, M.; Dulieu, O. Theory of Long-Range Ultracold Atom-Molecule Photoassociation. Phys. Rev. Lett. 2015, 115, 073201

[2] Elkamshishy, A. A.; Greene, C. H. Triatomic Photoassociation in an Ultracold Atom-

Molecule Collision. The Journal of Physical Chemistry A 2023, 127, 18–28, PMID:36584308