Dresden 2006 – wissenschaftliches Programm

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TT: Tiefe Temperaturen

TT 25: Correlated Electrons - Poster Session

TT 25.51: Poster

Mittwoch, 29. März 2006, 14:30–18:30, P1

Curie temperature in the Hubbard model with binary alloy disorder — •Krzysztof Byczuk¹, Martin Ulmke², and Dieter Vollhardt¹ — ¹Theoretical Physics III, Center for Electronic Correlations and Magnetism, Institute for Physics, University of Augsburg, 86135 Augsburg, Germany — ²FGAN-FKIE, Neuenahrer Str. 20, 53343 Wachtberg, Germany

Magnetic and electric properties of the Hubbard model with binary alloy disorder are studied within the dynamical mean-field theory. A paramagnet-ferromagnet phase transition and a Mott-Hubbard metal-insulator transition is found upon varying the alloy concentration. An enhancement of the Curie temperature due to disorder is demonstrated and is explained by the effects of band splitting and subband filling.

K. Byczuk and M. Ulmke, Eur. Phys. J. B 45, 449-454 (2005)

K. Byczuk, M. Ulmke, and D. Vollhardt, Phys. Rev. Lett. 90, 196403 (2003)