Universal Impedance Fluctuations in Wave Chaotic Systems

TL;DR

This paper experimentally confirms universal impedance fluctuations in wave chaotic systems, demonstrating that the statistical properties of the normalized cavity impedance match theoretical predictions when using radiation impedance to isolate universal behavior.

Contribution

The study provides experimental validation of theoretical predictions on universal impedance fluctuations in wave chaotic systems using microwave analogs and radiation impedance.

Findings

Excellent agreement between experimental data and theory.

Universal PDFs depend on a single loss parameter.

Variance of real and imaginary impedance parts are equal.

Abstract

We experimentally investigate theoretical predictions of universal impedance fluctuations in wave chaotic systems using a microwave analog of a quantum chaotic infinite square well potential. Our approach emphasizes the use of the radiation impedance to remove the non-universal effects of the particular coupling from the outside world to the scatterer. Specific predictions that we test include the probability distribution functions (PDFs) of the real (related to the local density of states in disordered metals) and imaginary parts of the normalized cavity impedance, the equality of the variances of these PDFs, and the dependence of the universal PDFs on a single control parameter characterizing the level of loss. We find excellent agreement between the statistical data and theoretical predictions.