Berlin 2005 – wissenschaftliches Programm
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TT: Tiefe Temperaturen
TT 16: Posters Correlated Electrons, Measuring Devices, Cryotechnique
TT 16.30: Poster
Samstag, 5. März 2005, 11:00–16:30, Poster TU C
The Role of Power-Law Correlated Disorder in the Anderson Metal-Insulator Transition — •A. Croy, V. Z. Cerovski, and M. Schreiber — Institut für Physik, Technische Universität, 09107 Chemnitz, Germany
The effect of long-range correlations of the form g(r)∝ r−α in classical systems, such as site or bond percolation problems, is well understood in terms of the extended Harris criterion [1]. It predicts a critical value αc=2/ν0 for the correlation strength, below which the correlations become relevant and the critical exponent changes from ν0 to ν=2/α. The question whether this criterion still holds for quantum systems is still under investigation. Recent results for ν in the Anderson model of localization in 3d suggest such a behavior for fixed disorder strength W, but not for a fixed energy E=0 at the band center [2]. We present results of the dependence of ν on α for both fixed W and fixed E, obtained using the finite size scaling of the largest inverse Lyapunov exponent of the transfer matrices of long quasi-1d systems.
[1] A. Weinrib, Phys. Rev. B29, 387 (1984)
[2] M. L. Ndawana, R. A. Römer and M. Schreiber, Europhys. Lett., Published online: 5 November 2004, doi:10.1209/epl/i2004-10267-5