Berlin 2008 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe
TT: Fachverband Tiefe Temperaturen
TT 23: Correlated Electrons: (General) Theory
TT 23.4: Vortrag
Mittwoch, 27. Februar 2008, 14:45–15:00, H 0104
Cluster Dual Fermion Approach to Nonlocal Correlations — •Hartmut Hafermann1, Sergey Brener1, Alexey N. Rubtsov2, Mikhail I. Katsnelson3, and Alexander I. Lichtenstein1 — 1I. Institute of Theoretical Physics, University of Hamburg, 20355 Hamburg, Germany — 2Department of Physics, Moscow State University, 119992 Moscow, Russia — 3Institute of Molecules and Materials, Radboud University, 6525 ED Nijmegen, The Netherlands
We formulate a cluster generalization to the recently developed Dual Fermion approach to nonlocal correlations in crystals.
The scheme allows the treatment of long-range correlations beyond the cluster DMFT and nonlocal effects in realistic calculations of multiorbital systems. It is shown that in the simplest approximation one exactly recovers the free-cluster DMFT. Recent results are presented, among them the application to the one-dimensional Hubbard model. Already the first dual fermion correction to the free cluster leads to a drastic improvement of the calculated Green function.