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DY: Fachverband Dynamik und Statistische Physik

DY 19: Quantum dynamics, decoherence and quantum information

DY 19.3: Talk

Wednesday, March 25, 2009, 17:30–17:45, ZEU 118

Statistical model for the effects of dephasing on transport properties of large samples — •Matías Zilly¹, Orsolya Ujsághy^1,2, and Dietrich E. Wolf¹ — ¹Department of Physics, University of Duisburg-Essen and CeNIDE, 47048 Duisburg, Germany — ²Department of Theoretical Physics and Condensed Matter Research Group of the Hungarian Academy of Sciences, Budapest University of Technology and Economics, Budafoki út 8., H-1521 Budapest, Hungary

We present a statistical model for the effects of dephasing on the transport properties of large devices. The physical picture is different from earlier models which assume that dephasing happens continuously throughout the sample, whereas we model the dephasing in a statistical sense, assuming a distribution of completely phase-randomizing regions between which the transport is coherent and described by the nonequilibrium Green's function method. Thus the sample is effectively divided into smaller parts making the numerical treatment more efficient. As a first application the conductances of ordered and disordered linear tight-binding chains are calculated and compared to the results of other phenomenological models in the literature.