Feasibility study of laser cooling of InF molecule

Electronic structure with spin-orbit coupling effect of HfH molecule for laser cooling investigations

The electronic structure, including the spin-orbit coupling effect of the HfH molecule, has been studied to determine if it can be cooled through Doppler and Sysphus laser cooling techniques. The multi-reference configuration interaction plus Davidson correction (MRCI + Q) method has been used to calculate its potential energy curves (P.E.C.s) in the Ω(±) and 2s+1Ʌ(+/-) representation. The spectroscopic constants Te, Re, ωe, Be, αe, the dipole moment µe, and the dissociation energies De agree very well with previously published work. In addition, we present in this work twenty new doublet and quartet states in the Ω(±) representation. The electronic transition dipole moment curves (TDMCs) between the lowest-lying electronic states have been investigated for the Δ - Π, Π - ∑+ and Δ - Φ transitions among specific Ω(±) states. The Franck-Condon factors (FCFs), the Einstein coefficient of spontaneous emission [Formula: see text] , and the radiative lifetime τ have been computed for the investigated transitions. In addition, properties of the molecules' electronic and vibrational states, such as the static dipole moment curves (D.M.C.s), the ionic character fionic, and the rovibrational constants are calculated. We deduce from our results that the HfH molecule is indeed a laser-cooling candidate that can reach a temperature as low as the nK regime. We present a complementary scheme with suitable experimental parameters. These results can be of great interest to experimental spectroscopists interested in ultracold diatomic molecules and their applications.

Spectroscopy and rovibrational cooling of AuF and its cation

The feasibility of laser cooling of AuF molecule and its cation are investigated from vibrational and rotational perspectives. The spectroscopy of AuF molecule and AuF⁺ molecular cation are obtained by the method of multireference configuration interaction plus Davidson correction (MRCI + Q) and spin-orbit coupling (SOC) effect. On account of the accurate molecular spectroscopy and the transition dipole moment, the Franck-Condon factors and radiative lifetimes of AuF molecule and AuF⁺ molecular cation are calculated. Comparing the criterias of laser cooling candidate molecules, the AuF is an excellent candidate for laser cooling and while AuF⁺ is not sutable. The b³Π₀₊ ↔ Χ¹Σ⁺₀₊ transition of AuF is selected for laser cooling and an optical cycling scheme is proposed. The scheme possesses highly diagonally Franck-Condon factors and the scattered photons achieve ∼ 10⁴. Furthermore, the rotational transition analysis is also included in our work and found that its Franck Condon factors and Einstein coefficients are undistorted. Our work could provide theoretical support and accelerate the laser cooling of AuF molecules in experiments.