Superconducting billiard cavities with chaotic dynamics: An experimental test of statistical measures

The eigenmodes of a superconducting, two-dimensional hyperbolically shaped cavity have been measured for frequencies below 20 GHz. These data of high accuracy, along with data from our previous measurement of a quarter stadium billiard [Gräf et al., Phys. Rev. Lett. 64, 1296 (1992)], are used as a test of three models (Brody, Berry and Robnik, Lenz and Haake) of distributions of eigenmodes. It becomes clear that data spanning universal and nonuniversal regimes and analyses extending at least up to two-level measures are essential to draw firm conclusions about the model descriptions.