Feasibility study of laser cooling of InF molecule

Abstract

ABSTRACTBy employing ab initio quantum chemistry method, we investigate the feasibility of laser cooling InF molecule. Four low-lying electronic states (X1Σ+, C1Π, 3Π and 23Π) of InF have been calculated using the multi-reference configuration interaction (MRCI) method. The spin-orbit coupling effects are also taken into account in the electronic structure computation at the MRCI level. The highly diagonal Franck-Condon factors for C1Π → X1Σ+ transitions are estimated. The radiative lifetime of the C1Π (v′ = 0) state is about 2.22 ns, which is found to be enough short for rapid laser cooling. Though the cooling wavelength of InF is located in the short-wavelength ultraviolet light (UVC), a frequency quadrupled Ti: sapphire laser (189–235 nm) could be capable of generating laser transition wavelength of InF. Furthermore, the C1Π → X1Σ+ transitions perhaps can be followed by the B3Π1 → X1Σ+0+ transitions to attain a lower Doppler temperature. Meanwhile, for achieving quasi-closed transition cycle of InF molecule, we investigate the hyperfine structure of the lowest state X1Σ+. Overall, the present results indicate the possibility of laser cooling InF molecules.