arXiv:cond-mat/0507729 · Physical Review B
Threshold behavior of bosonic two-dimensional few-body systems
D. Blume
Abstract
Bosonic two-dimensional self-bound clusters consisting of $N$ atoms interacting through additive van der Waals potentials become unbound at a critical mass ${m}_{*}^{(N)}$; ${m}_{*}^{(N)}$ has been predicted to be independent of the size of the system. Furthermore, it has been predicted that the ground state energy ${E}_{N}$ of the $N$-atom system varies exponentially as the atomic mass approaches ${m}_{*}$. This paper reports accurate numerical many-body calculations that allow these predictions to be tested. We confirm the existence of a universal critical mass ${m}_{*}$, and show that the near-threshold behavior can only be described properly if a previously neglected term is included. We comment on the universality of the energy ratio ${E}_{N+1}∕{E}_{N}$ near threshold.