Regensburg 2010 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 36: TR: Poster Session

TT 36.9: Poster

Donnerstag, 25. März 2010, 14:00–18:00, Poster A

Non-Equilibrium Dynamics of Electron Transport through Interacting Quantum Dots — •Alexander Croy and Ulf Saalmann — Max-Planck-Institut für Physik komplexer Systeme, Nöthnitzer Str. 38, 01187 Dresden, Germany

The transport of electrons through nanoscale devices, including quantum dot systems, has been a subject of intense research in the past decades. The study of time-resolved phenomena is of particular interest in this regard. This interest is driven not only by the prospect of realizing quantum computers using such systems, but also by the rapid experimental progress in this field.

In this context we study theoretically the time-resolved electric currents flowing through single and double quantum dots that are subject to a voltage pulse. Our numerical calculations are based on a recently developed propagation scheme for non-equilibrium Green functions [1]. This scheme relies on an efficient auxiliary-mode expansion of the Fermi function [2] and facilitates the study of arbitrary time-dependencies. We also present an extension of this scheme which allows treating interacting electrons for energies above the Kondo temperature. The results are compared to quantum master equations for the many-body density matrix describing the state of the quantum dot system.

[1] A. Croy and U. Saalmann, PRB, in print (2009), arXiv:0908.2936

[2] A. Croy and U. Saalmann, PRB 80, 073102 (2009)