Theoretical analysis of the coupling between Feshbach states and hyperfine excited states in the creation of ²³Na⁴⁰K molecule

We present an intensive study of the coupling between different Feshbach states and the hyperfine levels of the excited states in the adiabatic creation of ²³Na⁴⁰K ground-state molecules. We use coupled-channel method to calculate the wave function of the Feshbach molecules, and give the short-range wave function of triplet component. The energies of the hyperfine excited states and the coupling strength between the Feshbach states and the hyperfine excited states are calculated. Our results can be used to prepare a specific hyperfine level of the rovibrational ground state to study the ultracold collisions involving molecules.