Formation of molecular ions by radiative association of cold trapped atoms and ions

Formation d'ions moléculaires par association radiative d'atomes et d'ions froids piégés

Humberto da Silva Jr (1) , Maurice Raoult (1) , Mireille Aymar (1) , Olivier Dulieu (1)

1 LAC - Laboratoire Aimé Cotton

Radiative emission during cold collisions between trapped laser-cooled Rb atoms and alkaline-earth ions (Ca$^+$, Sr$^+$, Ba$^+$) and Yb$^+$, and between Li and Yb$^+$, are studied theoretically, using accurate effective-core-potential based quantum chemistry calculations of potential energy curves and transition dipole moments of the related molecular ions. Radiative association of molecular ions is predicted to occur for all systems with a cross section two to ten times larger than the radiative charge transfer one. Partial and total rate constants are also calculated and compared to available experiments. Narrow shape resonances are expected, which could be detectable at low temperature with an experimental resolution at the limit of the present standards. Vibrational distributions are also calculated, showing that the final molecular ions are not created in their ground state level.

Mots clés: cold molecular ions; effective core potentials; core polarization potentials; radiative association; quantum chemistry; cold collisions

Domaines: Physique Quantique [quant-ph]

Humberto da Silva Jr, Maurice Raoult, Mireille Aymar, Olivier Dulieu. Formation of molecular ions by radiative association of cold trapped atoms and ions. 2015. ⟨hal-01103444v2⟩