### Atomic, Molecular, and Optical Physics Seminar

Monday, December 10, 2018
4:00pm – 5:00pm

Storrs Campus
Physics Building, P121

Dr. Marko Gacesa, BAER Institute / NASA Ames Research Center

Photoassociation of ultracold molecular ions and controlling atom-ion charge exchange using magnetic Feshbach resonances

Feshbach resonances offer a way to control the strength and sign of particle-particle interactions in ultracold atomic and molecular gases by tuning external magnetic or electric fields. This discovery led to a number of experimental applications in ultracold AMO physics, in particular in preparation and production of dense samples of ultracold molecules. Because of their importance, Feshbach resonances have been measured and characterized in numerous of neutral diatomic mixtures. A natural generalization of studies of neutral ultracold gases includes atom-ion mixtures, which remain much less investigated than neutral systems. Atom-ion interactions are, generally, more difficult to investigate due to their long-range nature and presence of the charge. Nevertheless, the same properties also offer a window to investigate different physical regimes than the ones accessible by the neutral systems.

In this talk, I will present recent results, obtained in collaboration with the group of Prof. Robin Cote, related to using external magnetic and electric fields in controlling charge-exchange in atom-ion collisions. Specifically, I will present our theoretical investigation of magnetic Feshbach resonances and their application to controlled charge transfer in $${}^{9,10}$$Be + $${}^{9,10}$$Be+, and $${}^{40}$$Ca+$${}^{43}$$Ca+ both of which are good model systems for heavier and more complex elements. I will also present the results of first theoretical study of photoassociative formation of cold molecular ions, where we estimated the production rates of NaCa+ molecular ions from trapped cold Na+ ions and Ca atoms. This study is based on experiments conducted in the group of Prof. W. Smith at UConn.

Contact:

Prof. R. Cote

Physics Department (primary)