Ground state of small mixed helium and spin-polarized tritium clusters: a quantum Monte Carlo stud
Abstract
We report results for the ground-state energy and structural properties of small 4He-T clusters consisting of up to 4 T and 8 4He atoms. These results have been obtained using very well-known 4He-4He and T-T interaction potentials and several models for the 4He-T interatomic potential. All the calculations have been performed with variational and diffusion Monte Carlo methods. It takes at least three atoms to form a mixed bound state. In particular, for small clusters the binding energies are significantly affected by the precise form of the 4He-T interatomic potential but the stability limits remain unchanged. The only exception is the 4He2T trimer whose stability in the case of the weakest 4He-T interaction potential is uncertain, while it seems stable for other potentials. The mixed trimer 4He(T)2, a candidate for Borromean state, is not bound. All other studied clusters are stable. Some of the weakest bound clusters can be classified as quantum halos, as a consequence of having high probability of being in a classically forbidden region.