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The one‐dimensional 1/4‐filled Hubbard model with alternating interactions
Author(s) -
Japaridze G.,
Khomskii D.,
MüllerHartmann E.
Publication year - 1993
Publication title -
annalen der physik
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.009
H-Index - 68
eISSN - 1521-3889
pISSN - 0003-3804
DOI - 10.1002/andp.19935050105
Subject(s) - hubbard model , physics , condensed matter physics , commensurability (mathematics) , antiferromagnetism , excitation , superconductivity , coupling constant , metal–insulator transition , coupling (piping) , quantum mechanics , materials science , electrical resistivity and conductivity , geometry , mathematics , metallurgy
The one‐dimensional Hubbard model with different on‐site interaction on the even ( U a ) and odd ( U b ) sites is considered within the framework of the weak coupling approach. In the case of a 1/4‐filled band the dynamical nonequivalence of sites leads to the appearance of Umklapp processes in the system and to the dynamical generation of a commensurability gap in the charge excitation spectrum for U a ≠ U b and U a >0 or U b >0. Depending on the relation between the bare coupling constants the system shows four different regimes of behaviour in the infrared limit corresponding to normal metal, nonmagnetic insulator, antiferromagnetic insulator and superconducting states. The extended model including interaction between particles on nearest and next‐nearest neighbour sites is also considered.