Dresden 2006 – wissenschaftliches Programm

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HL: Halbleiterphysik

HL 21: Transport properties I

HL 21.11: Vortrag

Dienstag, 28. März 2006, 19:00–19:15, BEY 118

Admittance of open quantum systems — •Paul Racec^1,2, Roxana Racec^3,4, and Ulrich Wulf^3,1 — ¹IHP/BTU Joint Lab, Postfach 101344, 03013 Cottbus, Germany — ²National Institute of Materials Physics, PO Box MG-7, 077125 Bucharest Magurele, Romania — ³Technische Universität Cottbus, Fakultät 1, Postfach 101344, 03013 Cottbus, Germany — ⁴University of Bucharest, Faculty of Physics, PO Box MG-11, 077125 Bucharest Magurele, Romania

We present a formalism for the treatment of mesoscopic systems under a small time dependent bias superimposed to a static external bias which defines the working point. The scheme is based on linear response theory, where the unperturbed system is considered the system under the static external bias. For the unperturbed system, Hartree calculations are performed in the Landauer-Buettiker formalism. In order to describe the time dependent quantities, the corresponding response functions (charge-charge or current-charge correlations functions) are computed in the random phase approximation. Applications for blocking structures (like metal-insulator-semiconductor) and current carrying structures (like double barrier resonant tunneling diode) are presented. Based on quantum mechanical expressions for their admittance, equivalent small signal circuits are proposed.