26ème Congrès Général de la SFP

State-selective charge exchange in ion-molecule and three-body recombination in ion-atom-atom rubidium systems at the ultracold temperatures

Non programmé

20m

Centre des Congrès de la Villette (Cité des sciences et de l'Industrie, Paris)

Poster MC5 Physico-chimie des environnements atomiques et moléculaires froids et ultra froids Session Poster 1: MC3, MC5, MC6, MC11, MC13, MC15, MC16, MC18, MC19, MC25, REDP, posters hors MC

Orateur

Amrendra Pandey (Laboratoire Aimé Cotton, CNRS, Université Paris-Saclay, Orsay, France)

Description

We study the interactions between two Rb atoms and one Rb${}^{+}$ ion from a quantum chemistry perspective, considering the Rb${}_2$+Rb${}^{+}$ and Rb${}_2^{+}$+Rb arrangements. These interactions are relevant for the fundamental chemistry, sympathetic cooling, and three-body recombination (TBR) processes at ultra-low temperatures observed in hybrid ion-atom experiments for homo- and hetero-alkali ion-atom species, with Rb${}^{+}$ (or Ba${}^{+}$, Ca${}^{+}$)+Rb+Rb. Formation of Rb${}_2^{+}$ has recently been observed in inelastic collisions of a single cold Rb${}^{+}$ in a BEC of Rb atoms [1,2]. Another experiment has reported probable formation of molecular Rb${}_2$ in an hybrid ion-atom trap [3]. We start by calculating the electronic structure of the Rb${}_3^{+}$ ion using various approaches involving both large-core and small-core effective core potentials. We find that for specific geometry configurations, state-selective charge exchange reactions would occur for the ion-molecule Rb${}^{+}$+Rb${}_2$ system. We extend our investigations toward the large distance domain to elaborate on the transition from atom-molecule to three-atom configurations relevant to TBR, which could be responsible for molecular collision products Rb${}_2^{+}$ and Rb${}_2$. We show the generalization of these results for any alkali homo-nuclear three-body ion-molecule and ion-atom-atom systems.

Supported by the COCOTRAMOS project (Grant No. ANR-21-CE30-0060-01 “Agence Nationale de la Recherche”).

References

[1] T. Dieterle, M. Berngruber, C. H\"{o}lzl, R. L\"{o}w, K. Jachymski, T. Pfau, and F. Meinert, Phys. Rev. Lett. 126, 033401 (2021)

[2] T. Dieterle, M. Berngruber, C. H\"{o}lzl, R. L\"{o}w, K. Jachymski, T. Pfau, and F. Meinert, Phys. Rev. A 102, 041301 (2020).

[3] A. H\"{a}rter, A. Kr\"{u}kow, A. Brunner, W. Schnitzler, S. Schmid, and J. H. Denschlag, Phys. Rev. Lett. 109, 123201 (2012).