Dresden 2003 – wissenschaftliches Programm

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TT: Tiefe Temperaturen

TT 1: Mesoskopische Systeme I

TT 1.6: Vortrag

Montag, 24. März 2003, 11:00–11:15, HSZ03

Current Noise in ac-Driven Nanoscale Conductors — •Sigmund Kohler, Sébastien Camalet, Jörg Lehmann, and Peter Hänggi — Institut für Physik, Universität Augsburg

We study theoretically the current fluctuations in ac-driven transport through nanoscale systems. Our formalism is based on a generalized, non-Hermitian Floquet theory and allows to derive explicit expressions for the time-averaged current and the zero-frequency component of the current fluctuations. Different conduction channels can be distinguished by the number of absorbed, respectively emitted, photons. As an application, we investigate the influence of an ac-field on the transport through a quantum wire which is modelled by a tight-binding Hamiltonian. Both the zero-frequency noise and the dc-current can be suppressed by suitably chosen driving parameters. In the vicinity of such current suppressions, the Fano factor which characterizes the relative transport noise, exhibits distinct maxima and minima. These phenomena allow to devise current sources with a tunable noise level.

[1] S. Camalet, J. Lehmann, S. Kohler, and P. Hänggi, cond-mat/0212247.