2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/165428The exciton-exciton interaction is investigated for quasi-two-dimensional quantum structures. A bosonization scheme is applied including the full spin structure. For generating the effective interaction potentials, the Hartree-Fock and Heitler-London approaches are improved by a full two-exciton calculation which includes the van der Waals effect. With these potentials the biexciton formation in bilayer systems is investigated. For coupled quantum wells the two-body scattering matrix is calculated and employed to give a modified relation between exciton density and blue shift. Such a relation is of central importance for gauging exciton densities in experiments which pave the way toward Bose-Einstein condensation of excitons.Mesoscale and Nanoscale Physicstext