Understanding of surface states in a correlated electron system
Institut für Physik, Humboldt-Universität zu Berlin, Invalidenstraße 110, 10115
Published online: 15 August 2000
The aim of this work is to find a simple analytic model to explain some principal aspects of the behavior of surface states in correlated electron systems. We start from the analytic expression for the Green function of the semi-infinite tight binding linear chain. This Green function in case of modification of the center of gravity of the first atom and the change in coupling between the first and the second atom is evaluated as an exact analytic expression. Conditions for the existence and classification of surface states are given. The spectral weight of surface states and the local density of states are evaluated. The method is applied to a s.c. (100) surface of a local moment crystal. Conditions for the existence of surface states are derived and their locations in the Brillouin zone are predicted. It is shown that it is possible to include correlation effects within the framework of the discussed model. The comparison with former numerical results is performed.
PACS: 75.70.-i – Magnetic films and multilayers / 73.20.At – Surface states, band structure, electron density of states / 75.50.Pp – Magnetic semiconductors
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2000