Measurement of Parametric Correlations in Spectra of Resonating Quartz Blocks

Random matrix theory predicts parametric correlations for chaotic or disordered systems which are as universal as their spectral counterparts. However, an experimental verification of parametric correlations is, in the vast majority of systems, a difficult task, because the motion of individual levels has to be followed as an external parameter is varied. We present the first statistically highly significant result for a parametric correlator that uses solely experimental information. To this end, we measure the motion of acoustic resonances in quartz blocks as a function of its uniform temperature. We find some deviation between theoretical prediction and experimental results whose possible origin is discussed.