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%0 Thesis
%A Karrasch, Christoph
%T The functional renormalization group for zero-dimensional quantum systems in and out of equilibrium
%C Aachen
%I Publikationsserver der RWTH Aachen University
%M RWTH-CONV-124646
%P 219 S. : Ill., graph. Darst.
%D 2010
%Z Aachen, Techn. Hochsch., Diss., 2010
%X We study transport properties of quantum impurity systems using the functional renormalization group. The latter is an RG-based diagrammatic tool to treat Coulomb interactions in a fast and flexible way. Prior applications, which employed a simple first-order (Hartree-Fock-like) scheme to truncate the FRG flow equations within the Matsubara formalism, succeeded in accurately describing linear transport of various quantum dot geometries at zero temperature T=0. In a nutshell, advance in this Thesis is three-fold. First, we introduce a frequency-dependent second-order approximation in order to eventually compute finite-energy properties such as the conductance at T>0 (mainly focusing on the single impurity Anderson model). Second, a generalisation of the Hartree-Fock-like approach to Keldysh space allows for addressing the non-equilibrium steady-state dynamics of the interacting resonant level model. Third, we investigate the physics of a quantum dot Josephson junction as well as the charging of a single narrow level using the first-order scheme.
%K Renormierungsgruppe (SWD)
%K Quantenpunkt (SWD)
%K Nichtgleichgewicht (SWD)
%F PUB:(DE-HGF)11
%9 Dissertation / PhD Thesis
%U https://publications.rwth-aachen.de/record/63199