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DY: Dynamik und Statistische Physik
DY 15: Quantum Chaos
DY 15.1: Talk
Monday, March 27, 2006, 15:00–15:15, SCH 251
Fractal Classical Conductance Fluctuations — •Holger Hennig1, Ragnar Fleischmann1, and Lars Hufnagel2 — 1MPI for Dynamics and Self-Organization, Goettingen and Institute for Nonlinear Dynamics, University of Goettingen — 2Kavli Institute for Theoretical Physics, University of California, Santa Barbara
The coherent conductance through mesoscopic structures is well known
to show reproducible fluctuations with the variation of an external
parameter (e.g. a magnetic field). These fluctuations are caused by
interference effects and can be described semiclassically. In systems
with mixed regular and chaotic classical dynamics fractal conductance
curves are found [1]. Experiments that study the transition from
coherent to incoherent transport showing a change of the fractal
dimension with the coherence-length [2], however, seemed to contradict
the semiclassical theory of the fractal scaling.
We show that there is no contradiction but that the classical dynamics
itself already leads to fractal conductance curves explaining the
experimental observations. Moreover, we predict fractal classical
conductance fluctuations not only in systems with mixed phase space
but in purely chaotic systems.
[1] R. Ketzmerick, Phys. Rev. B, 54, 10841
[2] A.P. Micolich et al., Phys. Rev. Lett., 87, 036802