Berlin 2012 – scientific programme
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TT: Fachverband Tiefe Temperaturen
TT 34: Correlated Electrons: Metal-Insulator Transition 1
TT 34.4: Talk
Wednesday, March 28, 2012, 17:15–17:30, H 3010
The role of rotational symmetry in the magnetism of multiorbital Hubbard model — •Andrey Antipov1,2 and Alexey Rubtsov2 — 1Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Straße 40, 01187 Dresden, Germany — 2Moscow State University, Department of Physics, 1-2 Leninskiye Gory, 119991 Moscow, Russia
The effects associated with orbital fluctuations play an important role in the physics of strongly correlated electron systems. Examples worth noting are the orbital ordering effects and the orbital-selective Mott transition. A full quantitative description of these systems require taking into account the complete Coulomb interaction between the valence band electrons, a difficult task for quantum impurity solvers. This complexity often leads to taking into account only the density-density part of the Coulomb interaction which is diagonal in the orbital space. As it was shown in [1] this reduction can lead to a breakdown of a Kondo-peak in the metallic density of states of a multiorbital Hubbard model due to the change in the degree of the degeneracy of the ground state.
In order to access the finite-temperature regime the interaction-expansion quantum Monte Carlo impurity solver was employed. It is shown that taking into account the full rotationally invariant Coulomb interaction leads to double decrease of the metal-insulator transition temperature in a doubly-occupied three-band model and to a 20% change in a half-filled two-band and three-band models. The change in the density of states is compatible with the results of [1].
[1] Th. Pruschke and R. Bulla, Eur. Phys. J. B 44, 217 (2005)