https://doi.org/10.1140/epjb/e2005-00365-2
Ground states of the generalized Falicov-Kimball model in one and two dimensions
Institute of Experimental Physics, Slovak Academy of
Sciences Watsonova 47, 043 53 Košice, Slovakia
Corresponding author: a farky@saske.sk
Received:
6
July
2005
Published online:
17
November
2005
A combination of small-cluster exact-diagonalization calculations
and a well-controlled approximative method is used to study
the ground-state phase diagram of the spin-one-half
Falicov-Kimball model extended by the spin-dependent on-site interaction
between localized (f) and itinerant (d) electrons. Both the magnetic
and charge ordering are analysed as functions of the spin-dependent
on-site interaction (J) and the total number of itinerant (Nd) and
localized (Nf) electrons at selected U (the spin-independent
interaction between the f and d electrons).
It is shown that the spin-dependent interaction (for ,
where L is the number of lattice sites) stabilizes the fully polarized
(FP) and partially polarized (PP) state, while the stability
region of the non polarized (NP) phase is gradually reduced. The precisely
opposite effect on the stability of FP, PP and NP phases has a reduction
of Nf. Moreover, the strong coupling between the f and d-electron
subsystems is found for both
as well as
.
PACS: 75.10.Lp – Band and itinerant models / 71.27.+a – Strongly correlated electron systems; heavy fermions / 71.28.+d – Narrow-band systems; intermediate-valence solids / 71.30.+h – Metal-insulator transitions and other electronic transitions
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2005