Dresden 2006 – wissenschaftliches Programm

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TT: Tiefe Temperaturen

TT 5: Transport: Nanoelectronics I - Quantum Dots, Wires, Point Contacts - Part 1

TT 5.8: Vortrag

Montag, 27. März 2006, 11:45–12:00, HSZ 304

Non-adiabatic electron pumping: Maximal current with minimal noise — •Sigmund Kohler, Michael Strass, and Peter Hänggi — Institut für Physik, Universität Augsburg, 89135 Augsburg

The noise properties of pump currents through an open double quantum dot setup with non-adiabatic ac driving are investigated. Driving frequencies close to the internal resonances of the double-dot system mark the optimal working points at which the pump current assumes a maximum while its noise power exhibits a remarkably low minimum. Within a rotating-wave approximation, we derive for the current and its noise power analytical expressions, which allow to optimize the pump. For an inter-dot tunneling larger than the coupling between the dots and the electrodes, we find that the current noise is significantly below the shot noise level [1]. The analytical results are compared against numerically exact results from a Floquet transport theory [2]. The role of electron-electron interactions is studied within a master equation formalism.

[1] M. Strass, P. Hänggi, S. Kohler, Phys. Rev. Lett. 95, 130601 (2005).

[2] S. Kohler, J. Lehmann, P. Hänggi, Phys. Rep. 406, 379 (2005).