Genetics-based deperturbation analysis for the spin-orbit coupled ${ A}^1Σ^+$ and ${ b}^3Π0^+$ states of LiRb

We present a deperturbation analysis of the spin-orbit coupled A¹Σ⁺ and b³Π0⁺ states of LiRb based on the rovibrational energy levels observed previously by photoassociation spectroscopy in bosonic ⁷Li⁸⁵Rb molecule. Using the genetic algorithm, we fit the potential energy curves of the A¹Σ⁺ state and the b³Π state into point-wise form. We then fit these point-wise potentials along with the spin-orbit coupling into expanded Morse oscillator functional form and optimise analytical parameters based on the experimental data. From the fitted results, we calculate the transition dipole moment matrix elements for transitions from the rovibrational levels of the coupled A¹Σ⁺-b³Π0⁺ state to the Feshbach state and the absolute rovibrational ground state for fermionic ⁶Li⁸⁷Rb molecule. Based on the calculated transition dipole moment matrix elements, several levels of the coupled A¹Σ⁺-b³Π0⁺ state are predicted to be suitable as the intermediate state for stimulated Raman adiabatic passage transfer from the Feshbach state to the absolute rovibrational ground state. In addition, we also provide a similar estimation for B¹Π-c³Σ₁⁺-b³Π₁ state based on available $ab\ initio$ interaction potentials.