% IMPORTANT: The following is UTF-8 encoded. This means that in the presence % of non-ASCII characters, it will not work with BibTeX 0.99 or older. % Instead, you should use an up-to-date BibTeX implementation like “bibtex8” or % “biber”. @PHDTHESIS{Eissing:686159, author = {Eissing, Katharina}, othercontributors = {Meden, Volker and Schoeller, Herbert}, title = {{F}unctional renormalization group in {F}loquet space applied to periodically driven quantum dots}, school = {RWTH Aachen University}, type = {Dissertation}, address = {Aachen}, reportid = {RWTH-2017-02670}, pages = {1 Online-Ressource (vii, 131 Seiten) : Illustrationen, Diagramme}, year = {2017}, note = {Veröffentlicht auf dem Publikationsserver der RWTH Aachen University; Dissertation, RWTH Aachen University, 2017}, abstract = {The main goal of the present thesis is to set up a functional renormalization group formalism in Floquet space to treat interacting, time periodic quantum dots and to investigate the consequential renormalization of the parameters and the transport through the dot. Building upon the time independent, steady state description in frequency space (Karrasch 2010, Jakobs 2009) and a time dependent FRG formulation (Kennes 2014), we tackle the steady state of periodically driven quantum dots. We focus on the long time behavior where all transients have died out, and therefore the entire system is characterized by the same periodicity as given by the driven external fields. As a consequence, we can transform the according time dependent flow equation to Floquet space using Floquet-Green’s functions. It allows us to study quantum dot systems in the whole range of driving frequency and amplitude in the presence of a small Coulomb interaction. We exemplify the potential of our approach by applying it to the interacting resonant level model (IRLM), describing an idealized single level quantum dot dominated only by charge fluctuations.We investigate the role of the driving frequency Ω in the RG flows of the time periodic parameters of the IRLM. The small driving amplitude limit allows to complement our numerical solution by analytic expressions of the renormalization of all dot parameters to the leading order of driving amplitude over mean value. Four different configurations are studied, where distinct combinations of the hopping and/or onsite energy of the dot are chosen to be time periodic. The transparent structure of the renormalization of the parameters in this limit, allows for an analytic treatment of all higher harmonics, where the various protocols reveal very different RG flows. Even beyond the small driving amplitude limit the RG flow is discussed with the help of an effective reservoir distribution function which can be defined in this setup and its form is defined by the ratio of driving amplitude and frequency (Suzuki 2015). The second focus is directed to the transport in the time periodic quantum dot systems and how it is affected by the Coulomb interaction. Based on the well studied parameter pump in the adiabatic limit (Brouwer 1998), where two parameters are varied periodically and phase shifted, we like to investigate the pumped charge in the whole regime of driving frequency and amplitude including interaction in such a setup. Further a single parameter pump is realized and the charge susceptibility as well as the mean current are studied. The latter reveals power law behavior on the driving frequency. A quantum master equation calculation in Floquet-Liouville space complements the FRG results to study the requirements of such a single parameter quantum pump. Finally, the conductance and the current are considered for several time periodic hoppings of non-sinusoidal form.}, cin = {135820 / 130000}, ddc = {530}, cid = {$I:(DE-82)135820_20140620$ / $I:(DE-82)130000_20140620$}, typ = {PUB:(DE-HGF)11}, urn = {urn:nbn:de:hbz:82-rwth-2017-026701}, doi = {10.18154/RWTH-2017-02670}, url = {https://publications.rwth-aachen.de/record/686159}, }