Two interacting particles at a metal-insulator transition
Department of Computational Methods in Chemistry, Jagiellonian University, Ingardena
3, 30-060 Kraków, Poland
2 Institut für Physik, Technische Universität, 09107 Chemnitz, Germany
Published online: 15 April 1999
To investigate the influence of electronic interaction on the metal-insulator transition (MIT), we consider the Aubry-André (or Harper) model which describes a quasiperiodic one-dimensional quantum system of non-interacting electrons and exhibits an MIT. For a two-particle system, we study the effect of a Hubbard interaction on the transition by means of the transfer-matrix method and finite-size scaling. In agreement with previous studies we find that the interaction localizes some states in the otherwise metallic phase of the system. Nevertheless, the MIT remains unaffected by the interaction. For a long-range interaction, many more states become localized for sufficiently large interaction strength and the MIT appears to shift towards smaller quasiperiodic potential strength.
PACS: 71.30.+h – Metal-insulator transitions and other electronic transitions / 71.27.+a – Strongly correlated electron systems; heavy fermions / 72.15.Rn – Quantum localization / 71.23.Ft – Quasicrystals
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 1999