Bound States of Fermions on 2d Lattice in a Dilute Limit
M. Bąk and R. Micnas
Institute of Physics A. Mickiewicz University, Umultowska 85, 61-614 Poznań, Poland
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We examine extended bound states in a dilute limit of the extended Hubbard model on the two-dimensional square lattice. By solving exactly the two-body problem we have determined the binding energies, mobilities, and dispersion curves across the Brillouin zone for bound states of various symmetries. It turns out that the d-wave pairing is strongly favored by the nnn hopping and the intersite local pairs can have small effective masses, even in the case of strong binding.We have also found a possibility of extended s-dx2-y2 mixing of the bound states.
DOI: 10.12693/APhysPolA.97.209
PACS numbers: 74.20.-z, 03.65.Ge, 71.10.Fd