https://doi.org/10.1140/epjb/e2005-00261-9
Double exchange models: self consistent renormalisation
Harish-Chandra Research Institute, Chhatnag Road, Jhusi, Allahabad 211 019, India
Corresponding author: a pinaki@mri.ernet.in
Received:
2
January
2005
Published online:
18
August
2005
We propose a scheme for constructing classical spin Hamiltonians from Hunds
coupled spin-fermion models in the limit 
. The
strong coupling between fermions and the core spins requires self-consistent
calculation of the effective exchange in the model, either in the presence
of inhomogeneities or with changing temperature. In this paper we establish
the formalism and discuss
results mainly on the “clean” double exchange model,
with self consistently renormalised
couplings, and compare our results with exact simulations.
Our method allows access to system sizes much beyond the reach of exact
simulations, and we can study transport and optical properties of the model
without artificial broadening.
The method discussed here forms the foundation of our papers
[Phys. Rev. Lett. 91, 246602 (2003), and
Phys. Rev. Lett. 92, 126602 (2004)].
PACS: 71.15.Pd – Molecular dynamics calculations (Car-Parrinello) and other numerical simulations / 75.10.Hk – Classical spin models / 72.15.-v – Electronic conduction in metals and alloys
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2005
