Open AccessLOCAL APPROACH FOR THE EXTENDED HUBBARD MODEL
Author(s) -
Nie Hui-Quan,
Guozhu Wei,
Kaiyi Zhang
Publication year - 1988
Publication title -
wuli xuebao
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.199
H-Index - 47
ISSN - 1000-3290
DOI - 10.7498/aps.37.720
Subject(s) - antiferromagnetism , physics , hubbard model , paramagnetism , condensed matter physics , magnetic moment , superconductivity
In this paper, using the local approach, we calculated the correlation energy, the local moments and the polarisation around the local moments in paramagnetic phase up to second order in the extended Hubbard model. It is shown that the polarisation is always antiferro-magnetic for different values of W. The correlation energy increases with W increasing for n = 1 and large U. The local moments and the antiferromagnetic polarisation decrease with W increasing for fixed n and U. While the effect of W on both the local moments and the antiferromagnetic polarisation is not obvious for small n or for large U and n = 1.