Weakly Bound Triatomic He₂K And He₂Rb Molecules

In recent years, there are growing interests in searching for the weakly bound ground states of simple molecules for two reasons. One is due to an interest in finding the halo states or Efimov states of realistic atomic or molecular systems. The other is related to the creation of Bose-Einstein condensate (BEC) in various aggregates.The existence of the weakly bound He₂K and He₂Rb molecules are investigated. By employing the best empirical interaction between each pair of particles, the Schrodinger equation for the triatomic systems is solved using B-splines in the adiabatichyperspherical approximation. A bound state is found for each of the ⁴He - ⁴He - ³⁹K, ⁴He-³He-³⁹K ,³He-³He-³⁹K and ⁴He-⁴He-⁸⁵Rb , ⁴He-³He-⁸⁵Rb , ³He - ³He - ⁸⁵Rb trimers respectively. The bound state for the ³He - ³He - ³⁹K and ³He - ³He - ⁸⁵Rb molecules are the halo state found in realistic molecular systems forthere are no bound states in the ³He - ³He , ³He - ³⁹K and ³He - ⁸⁵Rb dimers. Byartificially adjusting the two-body interaction strength, the relation between the trimer binding energies and the interaction strengths is also discussed.