Laser assisted charge transfer in the realm of cold collisions

We study two colliding particles, Ca and Yb$^+$, which can undergo non-radiative charge-exchange transitions from the scattering continuum in the excited A$^2\Sigma^+$ state to the continuum of the ground X$^2\Sigma^+$ state. This reaction can be controlled by linearly-polarized laser radiation of frequency $\omega$, which is in the range of quasi-molecular electronic energy separation. Using the dressed-state picture or the Floquet Ansatz we construct coupled time-independent Schr\"odinger equations for the interatomic separation $R$. The mechanism of electromagnetic field control is based on an interplay between intra-molecular couplings and molecule-field interactions. We show that laser field affects the chemical reaction through reversible modification of an effective Hamiltonian via either non-resonant temporal Stark shifts or resonant ``dipolar'' interactions, leading to both transient- and cw-light-induced non-adiabatic charge transfer. We investigate these processes for various collision energies as well as over a wide range of laser intensities and frequencies.