https://doi.org/10.1140/epjb/e2005-00406-x
Mott transition in the asymmetric Hubbard model at half-filling within dynamical mean-field theory
Institute for Condensed Matter Physics of the National
Academy of Sciences of Ukraine, 1 Svientsitskii Str., 79011
Lviv, Ukraine
Corresponding author: a hera@icmp.lviv.ua
Received:
12
April
2005
Revised:
22
October
2005
Published online:
23
December
2005
The asymmetric Hubbard model with hopping integrals
dependent on an electron spin (particle sort) is studied using an
approximate analytic method within the dynamical mean-field
theory. The equations of motion for Hubbard operators followed by
projecting and different-time decoupling are used for solving the
single-site problem. Particle spectra are investigated at
half-filling within various approximations (Hubbard-I,
alloy-analogy and a generalization of the Hubbard-III
approximation). At half-filling these approximations can describe
only continuous gap opening in the spectrum.
The approach is used to describe the system between two limit
cases (the Falicov-Kimball model and the standard Hubbard model)
with continuous transition where 
is dependent on
the value of hopping parameters of different particles.
PACS: 71.10.Fd – Lattice fermion models (Hubbard model, etc.) / 71.27.+a – Strongly correlated electron systems; heavy fermions / 71.30.+h – Metal-insulator transitions and other electronic transitions
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2005
