Two-photon photoassociation spectroscopy of CsYb: Ground-state interaction potential and interspecies scattering lengths

Abstract

We perform two-photon photoassociation spectroscopy of the heteronuclear CsYb molecule to measure the binding energies of near-threshold vibrational levels of the X 2 Σ + 1/2 molecular ground state. We report results for 133 Cs 170 Yb, 133 Cs 173 Yb and 133 Cs 174 Yb, in each case determining the energy of several vibrational levels including the least-bound state. We fit an interaction potential based on electronic structure calculations to the binding energies for all three isotopologs and find that the ground-state potential supports 77 vibrational levels. We use the fitted potential to predict the interspecies s-wave scattering lengths for all seven Cs+Yb isotopic mixtures.

Ultracold polar molecules as qudits

“…S 2 is the electronic ground state of molecules such as SrF [50], CaF [51,52], YbF [78] and YO [53], which have been recently laser cooled. Molecules formed by associating an alkali atom and a closed-shell atom [79][80][81] will also have 2 Σ ground states. To illustrate our discussion, we consider the specific cases of 40 Ca 19 F and 87 Rb 133 Cs molecules.…”

Absolute numbering of asymptotic vibrational levels of diatomic molecules from cold-physics experiments

“…Their absolute vibrational numbers were found using formula (2) and they are listed in Table II. The experimental accuracy for RbSr molecule is comparable to that for CsYb [3], so the uncertainties of the vibrational numbers are also comparable. Again the present simple approach is in agreement with the analysis from Ref.…”

“…Since the least bound level is labelled in Ref. [3] with relative vibrational quantum number n = −1 and the labels decrease for stronger bound levels, we adopted the same numbering here. The experimental uncertainty of binding energies reported in Table I of Ref. [3] varies from 0.1 MHz to 2 MHz.…”

“…If however n = −1 corresponds to v = 76, only one calculated v (the one for n = −1 in Cs 173 Yb with v = 77.1) deviates by more than 1, while the average deviation for all five data is ∆v ave = −0.24 -a much better agreement. So v = 76 is a much more reasonable choice for the label n = −1 which is also the result of the more intricate analysis in [3].…”

“…In a series of recently published papers, measurements of binding energies for the few last rovibrational levels in the ground electronic state were reported in RbYb [1], Yb 2 [2], CsYb [3] and RbSr [4] molecules. These studies were focused on the scattering properties of the corresponding ultra-cold atomic species, including the interatomic interaction potentials and scattering lengths.…”