Formation of a molecular ion by photoassociative Raman processes

Abstract

We show theoretically that it is possible to form a cold molecular ion from a pair of colliding atom and ion at low energy by photoassociative two-photon Raman processes. We explore the possibility of stimulated Raman adiabatic passage from the continuum of ion-atom scattering states to an ionic molecular state. We provide physical conditions under which coherent population transfer is possible in stimulated Raman photoassociation. Our results are important for experimental realization of PA in ion-atom cold collisions.

Spectroscopic properties of the molecular ions BeX+ (X=Na, K, Rb): forming cold molecular ions from an ion–atom mixture by stimulated Raman adiabatic process

“…The adiabatic condition for this type of system can be expressed as dβ dt ≪ k b T / , where k b is Boltzmann constant and T is temperature of the system. The detailed of this quasi-DS and adiabatic condition for our model system has been discussed in the reference [37]. In this section we present result for the formation of molecular ion of the dis-cussed ion-atom colliding systems.…”

“…Here, | E is initially populated ion-atom scattering continuum of 2 where B 1E , B 2E , F E (E ′ ) are expansion coefficients. The detailed derivations are done in the paper [37]. As | E dr is energy normalized, so we can write…”

“…But systems involving a continuum such as two-atom or ion-atom collisional continuum, complete population transfer is difficult by this coherent method as it is impossible to form a transparent DS at all energies. In a recent theoretical paper on continuum-bound-bound system resembling Λ-type configuration [37], it is shown that the population in the continuum of ion-atom scattering states can be partially transferred to a target state via STIRAP-like fashion and the system follows a quasi-DS condition.…”

Cold hybrid ion-atom systems

“…(Rakshit and Deb, 2011) considered theoretically the photoassociative formation of LiBe + molecular ions, whereas (Sardar et al, 2016) explored the formation of ground-state LiCs + molecular ions by photoassociation and stimulated Raman adiabatic passage.…”

Charge transfer in ultracold gases via Feshbach resonances

“…Of particular interest are applications of such hybrid systems to atom-ion interactions and chemistry [19][20][21][22][23], precision measurements [24], many-body physics [2,[25][26][27][28][29][30][31], and quantum information processing [32,33]. In addition, a number of theoretical proposals suggest different approaches to forming ultracold molecular ions in their ground state [34][35][36][37][38][39][40][41]. Developing a solid understanding of two-body atom-ion interactions at ultra-low temperatures, and the means to control them e.g., using external electric, magnetic, or optical fields, is central to advancing such research and constitutes an essential step towards envisioning new experiments and developing many-body theoretical descriptions.…”