Bärnthaler, A. (2009). Beutler-Fano resonances with time-dependence and decoherence : a theoretical and experimental study [Diploma Thesis, Technische Universität Wien]. reposiTUm. http://hdl.handle.net/20.500.12708/184827
Beutler-Fano resonances occuring in transport through a rectangular cavity are studied. They emerge from the interaction of a resonant and a non-resonant path through the cavity. Beutler-Fano resonances provide a means to measure the degree of decoherence present in the cavity. Two different types of decoherence, microwave attenuation and dephasing according to the voltage probe model, are shown to have a characteristically different influence on Beutler-Fano resonances, characterized by a complex Fano q parameter. We verify our theoretical results by measuring transport through microwave cavities made of three different materials, corresponding to a range of decoherence strengths. The time-dependent propagation of a pulse through the rectangular cavity is investigated both theoretically and experimentally. In the time-resolved Fourier spectrum of the pulse transmitted through the cavity, transient hyperbolic interference patterns occur which allow for the extraction of resonance parameters.
