2026-04-05T12:51:15Zhttps://recercat.cat/oai/request

oai:recercat.cat:2117/3306572026-02-02T09:23:38Zcom_2072_1033col_2072_452950

00925njm 22002777a 4500 dc Guijarro Gámez, Grecia author Astrakharchik, Grigori author Boronat Medico, Jordi author Bazak, Betzalel author Petrov, D. S. author 2020-04-07 We study clusters of the type $A_NB_M$ with N=M=3 in a two-dimensional mixture of A and B bosons, with attractive AB and equally repulsive AA and BB interactions. In order to check universal aspects of the problem, we choose two very different models: dipolar bosons in a bilayer geometry and particles interacting via separable Gaussian potentials. We find that all the considered clusters are bound and that their energies are universal functions of the scattering lengths $a_{AB}$ and $a{AA}=a_{BB}$, for sufficiently large attraction-to-repulsion ratios $a_{AB}/a_{BB}$. When $a_{AB}/a_{BB}$ decreases below ˜10, the dimer-dimer interaction changes from attractive to repulsive and the population-balanced AABB and AAABBB clusters break into AB dimers. Calculating the AAABBB hexamer energy just below this threshold, we find an effective three-dimer repulsion which may have important implications for the many-body problem, particularly for observing liquid and supersolid states of dipolar dimers in the bilayer geometry. The population-imbalanced ABB trimer, ABBB tetramer, and AABBB pentamer remain bound beyond the dimer-dimer threshold. In the dipolar model, they break up at $a_{AB}˜2a_{BB}, where the atom-dimer interaction switches to repulsion. Postprint (published version) Àrees temàtiques de la UPC::Física Bosons Bosons Bound states Few-body systems Bosons Few-body bound states of two-dimensional bosons