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TT: Fachverband Tiefe Temperaturen
TT 29: TR: Nanoelectronics I: Quantum Dots, Wires, Point Contacts 1
TT 29.12: Vortrag
Donnerstag, 25. März 2010, 12:30–12:45, H19
Quantum Monte Carlo simulations for contacted quantum dots — •Lothar Mühlbacher1 and Klaus Ferdinand Albrecht2 — 1Physikalisches Institut, Albert-Ludwigs-Universität, Freiburg, Germany — 2Institut für theoretische Physik, Ruprecht-Karls-Universität, Heidelberg, Germany
Correlated transport through nanostructures can prototypically be studied in the framework of the Anderson impurity model. It comprises of a single, spin degenerate electronic level which couples via tunneling to two (or more) metallic electrodes. Although analytic solutions exist for many of its equilibrium properties, the non-equilibrium case, when the electrodes are subject to a finite voltage bias, is yet to be fully understood.
In recent years, real-time diagrammatic Monte Carlo (MC) techniques have emerged as a new and promising tool for a quantitative analysis of the non-equilibrium transport properties. For a large range of parameters, the transient as well as stationary transport properties can be calculated in a numerically exact way. Since diagrammatic MC schemes impose rather few restrictions with respect to the modeling of the electrodes, they also allow to include time-dependent tunneling couplings or to measure the quantum dot's spectral density via a three-terminal setup. Furthermore, in combination with path-integral techniques, diagrammatic MC methods are also capable of accessing the dynamics of a quantum dot coupled to a heat reservoir. Thus, in addition to electronic correlations, the influence of electron-phonon interactions on the transport properties can be studied as well.