Microwave studies of open systems with complex dynamics
Zusammenfassung der Projektergebnisse
Complex wave systems had been studied by means of microwave techniques. Eleven different topics had been approached resulting in joint publications with four other P projects and with four external E projects. The following topics had been addressed: (i) Investigation of “rogue waves”: The algebraic -2/3 decay in the scintillation index characterizing branched flow was observed experimentally. (ii) Reappearance of regular states: In a mushroom billiard the reappearance of partially flooded regular states after opening the system was found. In a cosine billiard resonance assisted tunneling was found. (iii) Non-linear effects in the side band structure of Floquet systems: By driving the electrical properties of a “tin”-resonator we observed a hysteresis effect in the Floquet side band structure. (iv) Goos-Hänchen shift and Fresnel filtering: Generating a plane wave by superimposing measurements from different antenna positions, we observed a shift of the outgoing wave reflected from an teflon-air interface. (v) Skipping orbits: Using a quasi-one-dimensional wave guide with surface roughness we were able to separate two different scattering mechanisms by introducing appropriate correlations in the disorder. (vi) Metamaterials in disordered one-dimensional waveguides: We realized metamaterial by means of coupled split ring resonators. In a free space measurement a frequency range was found with a negative index of refraction. Unfortunately this effect vanished inside a wave guide. (vii) Classical features in the fidelity decay: By changing the shape of a chaotic cavity by means of a piston-like perturbation a non-monotonic behaviour of the fidelity as a function of the perturbation strength was found. (viii) Cross-section correlations: We found that the cross-section correlation with only one index in common compared to the correlation without any index in common were anticorrelated as a function of the coupling strength. (ix) Graphene-like structures with microwaves: We realized a tight binding microwave system using dielectric cylinders with a high index of refraction (n=6). With this setup we were able to investigate graphene like structures with disorder, boron nitride but also a Dirac oscillator. (x) Resonances in systems with a fractal classical repeller: The fractal Weyl law and the the predicted minimal resonance width in a three and five disk system was verified experimentally. (xi) Nearest level spacing statistics in open chaotic systems: The Wigner distributions for the nearest neighbour spacing distribution have to be modified for open systems. Using a 2 × 2 matrix approach an analytic description was derived and verified experimentally.
Projektbezogene Publikationen (Auswahl)
- Dirac point and edge states in a microwave realization of tight-binding graphene-like structures. Phys. Rev. B 82, 094308 (2010)
U. Kuhl, S. Barkhofen, T. Tudorovskiy, H.-J. Stöckmann, T Hossain, L. de Forges de Parny, and F. Mortessagne
(Siehe online unter https://doi.org/10.1103/PhysRevB.82.094308) - Microwave fidelity studies by varying antenna coupling. Phys. Rev. E 82, 036207 (2010)
B. Köber, U. Kuhl, H.-J. Stöckmann, T. Gorin, D. V. Savin, and T. H. Seligman
(Siehe online unter https://doi.org/10.1103/PhysRevE.82.036207) - Fidelity decay for local perturbations: Microwave evidence for oscillating decay exponents. Phys. Rev. E 83, 016214 (2011)
B. Köber, U. Kuhl, H.-J. Stockmann, A. Goussev, and K. Richter
(Siehe online unter https://doi.org/10.1103/PhysRevE.83.016214) - Measurement of the Goos-Hänchen shift in a microwave cavity. New J. of Physics 13, 023013 (2011)
J. Unterhinninghofen, U. Kuhl, J. Wiersig, H.-J. Stöckmann, and M. Hentschel
(Siehe online unter https://doi.org/10.1088/1367-2630/13/2/023013) - Nearest level spacing statistics in open chaotic systems: Generalization of the Wigner surmise. Phys. Rev. Lett. 108, 174101 (2012)
C. Poli, G. A. Luna-Acosta, and H.-J. Stöckmann
(Siehe online unter https://doi.org/10.1103/PhysRevLett.108.174101) - Experimental observation of a fundamental length scale of waves in random media. Phys. Rev. Lett. 111,183902 (2013)
S. Barkhofen, J. J. Metzger, R. Fleischmann, U. Kuhl, and H.-J. Stöckmann
(Siehe online unter https://doi.org/10.1103/PhysRevLett.111.183902) - Experimental observation of the spectral gap in microwave n-disk systems. Phys. Rev. Lett. 110,164102 (2013)
S. Barkhofen, T Weich, A. Potzuweit, H.-J. Stöckmann, U. Kuhl, and M. Zworski
(Siehe online unter https://doi.org/10.1103/PhysRevLett.110.164102) - First experimental realization of the Dirac oscillator. Phys. Rev. Lett. 111, 170405 (2013)
J. A. Franco-Villafane, E. Sadurni, S. Barkhofen, U. Kuhl, F. Mortessagne, and T H. Seligman
(Siehe online unter https://doi.org/10.1103/PhysRevLett.111.170405) - Microwave realisation of a periodically driven system. New J. of Physics 15, 083030 (2013)
S. Gehler, T. Tudorovskiy, C. Schindler, U. Kuhl, and H.-J. Stöckmann
(Siehe online unter https://doi.org/10.1088/1367-2630/15/8/083030)
