Interatomic potentials, electric properties and spectroscopy of the ground and excited states of the Rb₂ molecule: ab initio calculations and effect of a non-resonant field*

Abstract

We formulate the theory for a diatomic molecule in a spatially degenerate electronic state interacting with a non-resonant laser field and investigate its rovibrational structure in the presence of the field. We report on ab initio calculations employing the double electron attachment intermediate Hamiltonian Fock space coupled cluster method restricted to single and double excitations for all electronic states of the Rb 2 molecule up to 5s + 5d dissociation limit of about 26.000 cm −1 . In order to correctly predict the spectroscopic behavior of Rb 2 , we have also calculated the electric transition dipole moments, non-adiabatic coupling and spin-orbit coupling matrix elements, and static dipole polarizabilities, using the multireference configuration interaction method. When a molecule is exposed to strong non-resonant light, its rovibrational levels get hybridized. We study the spectroscopic signatures of this effect for transitions between the X 1 Σ + g electronic ground state and the A 1 Σ + u and b 3 Πu excited state manifold. The latter is characterized by strong perturbations due to the spin-orbit interaction. We find that for non-resonant field strengths of the order 10 9 W/cm 2 , the spin-orbit interaction and coupling to the non-resonant field become comparable. The non-resonant field can then be used to control the singlet-triplet character of a rovibrational level.

Ground- and excited-state properties of the polar and paramagnetic RbSr molecule: A comparative study

“…The ∆α at equilibrium distance is very large and comparable to the largest anisotropies reported for alkali-metal dimers [7,72]. With the large dipole moment and the large anisotropy of polarizability of RbSr, the RbSr molecule can be considered as a good candidate for manipulation with intense off-resonant laser light [73][74][75]. Figure 4 shows the diagram of the excited energy levels of Rb and Sr and lists the related Hund's (a) case states of RbSr.…”

Reexamination of the calculation of two-center, two-electron integrals over Slater-type orbitals. III. Case study of the beryllium dimer

“…[4] for interpretation of the observed subradiant states of Sr 2 . Electronic structure calculations can also be used to predict new schemes for the formation of ultracold diatomic molecules [5][6][7][8][9]. Apart from that, state-ofthe-art first-principles calculations are used in metrology e.g.…”

Combining Slater-type orbitals and effective core potentials

“…[56][57][58][59][60][61] for joint experimental and theoretical studies of new spectroscopic features of the strontium molecule. Electronic structure calculations can also be used to predict new schemes for the formation of ultracold diatomic molecules [62][63][64][65][66][67]. Accurate interatomic interaction potentials are also of great importance in search for a new physics, see e.g., the work on the YbF molecule which is used in measurements of the permanent electric dipole moment (EDM) of the electron [68], and determination of the proton-electron mass ratio time variation [69].…”