Formation of deeply bound ultracold Sr_2 molecules by photoassociation near the ^1S + ^3P_1 intercombination line

Abstract

We predict feasibility of the photoassociative formation of Sr_2 molecules in arbitrary vibrational levels of the electronic ground state based on state-of-the-art ab initio calculations. Key is the strong spin-orbit interaction between the c^3Π_u, A^1Σ_u^+ and B^1Σ_u^+ states. It creates not only an effective dipole moment allowing free-to-bound transitions near the ^1S + ^3P_1 intercombination line but also facilitates bound-to-bound transitions via resonantly coupled excited state rovibrational levels to deeply bound rovibrational levels of the ground X^1Σ_g^+ potential, with v" as low as v"=6. The spin-orbit interaction is responsible for both optical pathways. Therefore, those excited state levels that have the largest bound-to-bound transition moments to deeply bound ground state levels also exhibit a sufficient photoassociation probability, comparable to that of the lowest weakly bound excited state level previously observed by Zelevinsky et al. [Phys. Rev. Lett. 96, 203201 (2006)]. Our study paves the way for an efficient photoassociative production of Sr_2 molecules in ground state levels suitable for experiments testing the electron-to-proton mass ratio.

11 pages, 10 figures

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Cited by in corpus (11)

• Rovibrational dynamics of the strontium molecule in the A^1Σ_u^+, c^3Π_u, and a^3Σ_u^+ manifold from state-of-the-art ab initio calculations
• Mass scaling and non-adiabatic effects in photoassociation spectroscopy of ultracold strontium atoms
• Thermometry via Light Shifts in Optical Lattices
• A terahertz vibrational molecular clock with systematic uncertainty at the $10^{-14}$ level
• Optimized production of ultracold ground-state molecules: Stabilization employing potentials with ion-pair character and strong spin-orbit coupling
• Calculation of two-centre two-electron integrals over Slater-type orbitals revisited. III. Case study of the beryllium dimer
• Enhancing photoassociation rates by non-resonant light control of shape resonances
• Ultracold ${}^{88}{\mathrm{Sr}}_2$ molecules in the absolute ground state
• Analytical two-center integrals over Slater geminal functions
• Relativistic calculations of $C_6$ and $C_8$ coefficients for strontium dimers
• Asymptotic model for shape resonance control of diatomics by intense non-resonant light