Extensive theoretical studies of the highly excited electronic states with the experimental parameters calculation for the laser cooling of CaI molecule

Abstract

By using the multireference configuration interaction method followed by Davidson correction, the electronic structure of the molecule CaI has been investigated. The potential energy curves, the permanent and transition dipole moment curves, and the spectroscopic parameters of 18 electronic states are investigated for these states, along with 111 vibrational levels of the four lowest electronic states. The Franck–Condon factors and the radiative lifetime are calculated for the X2Σ+–(1)2Π transition. For this transition, the vibrational branching ratio, the slowing distance L, and the number of cycles ( N) for photon absorption/emission are calculated along with the Doppler and the recoil temperatures. A pre-cooling temperature in a helium buffer gas is studied and a laser cooling scheme is presented. The calculation of these different experimental parameters is crucial to exploring the optimal conditions under which the laser cooling experiment of CaI molecule will be performed.