Regensburg 2007 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 20: Correlated Electrons - Poster Session

TT 20.60: Poster

Mittwoch, 28. März 2007, 14:00–17:45, Poster A

Effect of disorder on ferromagnetism in the periodic Anderson model within dynamical mean-field theory — •Unjong Yu, Krzysztof Byczuk, and Dieter Vollhardt — Theoretical Physics III, Center for Electronic Correlations and Magnetism, Institute for Physics, University of Augsburg, D-86135 Augsburg, Germany

Dynamical mean-field theory (DMFT) has been successfully applied to study of magnetism in strongly correlated systems, especially the Hubbard model [1] and the periodic Anderson model (PAM) [2]. DMFT was also shown to be an adequate tool to investigate the effect of disorder on magnetism in the Hubbard model [3]. In this presentation, we examine the stability of ferromagnetism in the PAM in the presence of binary alloy disorder by using the DMFT together with the quantum Monte-Carlo method. The magnetic phase diagram of the PAM as a function of disorder strength and alloy concentration as well as a carrier density is discussed.

[1] D. Vollhardt, N. Blümer, K. Held, M. Kollar, J. Schlipf, M. Ulmke, and J. Wahle, Advances in Solid State Physics 38, 383 (1999).

[2] A. N. Tahvildar-Zadeh, M. Jarrell, and J. K. Freericks, Phys. Rev. B 55, R3332 (1997).

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