Berlin 2008 – wissenschaftliches Programm
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TT: Fachverband Tiefe Temperaturen
TT 28: Correlated Electrons: Metal-Insulator Transition 1
TT 28.4: Vortrag
Donnerstag, 28. Februar 2008, 10:15–10:30, H 2053
Mott-Hubbard transition in a two-band model: From three to two dimensions — •Philipp Hansmann, Xiaoping Yang, Alessandro Toschi, Giniyat Khaliullin, Ole Krogh Andersen, and Karsten Held — Max Planck Institute for Solid State Research, Stuttgart
The influence of dimensionality on the Mott-Hubbard transition in a two-band model is studied. More specifically we consider a two eg-band Hubbard model at quarter filling which is analyzed within dynamical mean field theory. Nearest neighbor hopping and hybridization are taken into account as well as a small crystal-field splitting of the two eg-bands. Starting from the three dimensional cubic symmetry the hopping in the crystallographic z-direction is tuned to zero where results for the two dimensional system are recovered. Although electronic correlations on surfaces and in two dimensions are expected to be stronger than in the three dimensional case, our results show that this effect is weakened as a result of the hybridization between the two eg-orbitals.