Multiexciton molecules in the hexaborides
Institut für Theoretische Physik, ETH-Hönggerberg,
8093 Zurich, Switzerland
Corresponding author: a email@example.com
Published online: 15 June 2001
We investigate multiexciton bound states in a semiconducting phase of divalent hexaborides. Due to three degenerate valleys in both the conduction and valence bands the binding energy of a 6-exciton molecule is greatly enhanced by the shell effect. The ground state energies of multiexciton molecules are calculated using the density functional formalism. We also show that charged impurities stabilize multiexciton complexes leading to condensation of localized excitons. These complexes can act as nucleation centers of local moments.
PACS: 71.35.-y – Excitons and related phenomena / 71.35.Lk – Collective effects (Bose effects, phase space filling, and excitonic phase transitions) / 77.84.Bw – Elements, oxides, nitrides, borides, carbides, chalcogenides, etc.
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2001