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TT: Tiefe Temperaturen

TT 25: Correlated Electrons - Poster Session

TT 25.65: Poster

Wednesday, March 29, 2006, 14:30–18:30, P1

Non-equilibrium properties of quantum impurity systems from the functional renormalization group approach — •Riccardo Gezzi, Thomas Pruschke, and Volker Meden — Institut für Theoretische Physik, Universität Göttingen, Friedrich-Hund-Platz 1, 37077 Göttingen

The functional renormalization group approach is extended to handle stationary non-equlibrium problems. As first application we study a quantum-dot system subject to a finite bias voltage. As approximations to the flow-equation scheme we employ truncation at zero and one-loop order, ignoring energy dependencies in the latter.

Since in the limit of vanishing bias voltage an analytical solution to the differential equation generated in the zero-loop approximation exists, we can discuss the analytic structure of the solution to the flow equations obtained and show that in contrast to the equilibrium formulation poles in the right hand side can lead to an ill-conditioned problem for numerical differential equation solver.

First results for non-equilibrium properties of the single-impurity Anderson model will be discussed.