title: Probing decoherence through Fano resonances.
abstract: We investigate the effect of decoherence on Fano resonances in wave transmission through resonant scattering structures. We show that the Fano asymmetry parameter q follows, as a function of the strength of decoherence, trajectories in the complex plane that reveal detailed information on the underlying decoherence process. Dissipation and unitary dephasing give rise to manifestly different trajectories. Our predictions are successfully tested against microwave experiments using metal cavities with different absorption coefficients and against previously published data on transport through quantum dots. These results open up new possibilities for studying the effect of decoherence in a wide array of physical systems where Fano resonances are present.
authors.affiliation: Institute for Theoretical Physics, Vienna University of Technology, A-1040 Vienna, Austria, EU.
authors.forename: Andreas
authors.initials: A
authors.lastname: Bärnthaler
authors.forename: Stefan
authors.initials: S
authors.lastname: Rotter
authors.forename: Florian
authors.initials: F
authors.lastname: Libisch
authors.forename: Joachim
authors.initials: J
authors.lastname: Burgdörfer
authors.forename: Stefan
authors.initials: S
authors.lastname: Gehler
authors.forename: Ulrich
authors.initials: U
authors.lastname: Kuhl
authors.forename: Hans-Jürgen
authors.initials: HJ
authors.lastname: Stöckmann