In complex materials where electrons occupy 3d-, 4f- or 5f-orbitals the
excitation spectra cannot be described in terms of well-defined
quasiparticles over a wide range of temperatures and frequencies.
Single-electron descriptions using a mean-field break down and strong
correlations come into play. The dynamical mean-field theory provides an
approach that contains both band and atomic physics as limiting cases and
can serve as a basis of a new spectral functional theory which allows to
quantitatively describe the excitation spectra of complex strongly
correlated materials.
References:
- G. Kotliar and D. Vollhardt, Strongly Correlated Materials: Insights
from Dynamical Mean-Field Theory, Physics Today 57, No. 3 (March),
53 (2004).
- A. Georges, G. Kotliar, W. Krauth, M. Rozenberg, The Local Impurity
Self Consistent Approximation to Strongly Correlated Fermion Systems and the
Limit of Infinite Dimensions, Rev. Mod. Phys. 68, 13 (1996).
Further reading can be found at the web pages of Dieter Vollhardt's group in
Augsburg: http://www.physik.uni-augsburg.de/theo3/vollha
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