C. Dembowski

First experimental evidence for quantum echoes in scattering systems.

A self-pulsing effect termed quantum echoes has been observed in experiments with an open superconducting and a normal conducting microwave billiard whose geometry provides soft chaos, i.e., a mixed phase space portrait with a large stable island. For such systems a periodic response to an incoming pulse has been predicted. Its period has been associated with the degree of development of a horseshoe describing the topology of the classical dynamics. The experiments confirm this picture and reveal the topological information.

Quantum chaos and wavedynamical chaos in two- and three-dimensional microwave billiards☆

Abstract Examples of recent experiments with microwave resonators in two- and three-dimensions in which we study the quantum manifestation of classical chaos in systems with few degrees of freedom are presented. We show the application of random matrix theory and periodic orbit theory to different experimental systems, the spectral features of coupled billiards with varying strength and results on Anderson localization in a simple Bloch-like lattice.

Experimental Test of the Trace Formula by Balian and Duplantier

Trace formulas provide a direct relation between the eigenvalues of a given quantum system and the properties of the periodic orbits of its classical counterpart. About 25 years ago, Balian and Duplantier derived a trace formula for the resonance density of three-dimensional chaotic microwave cavities. We will present the first experimental test of this semiclassical approximation performed with a microwave cavity of the shape of a three-dimensional Bunimovich billiard.