Boundary losses and spatial statistics of complex modes in a chaotic microwave cavity

TL;DR

This study investigates how boundary ohmic losses affect resonance widths and wavefunction complexity in a chaotic microwave cavity, revealing a single parameter linking damping and wavefunction complexity.

Contribution

It experimentally links boundary losses to wavefunction complexity and introduces a parameter quantifying this relationship in chaotic wave systems.

Findings

Boundary losses cause non-proportional resonance widths.

Non-proportional widths relate to wavefunction complexity.

A single parameter measures the complexity of wavefunctions.

Abstract

We experimentally study the various manifestations of ohmic losses in a two-dimensional microwave chaotic cavity and exhibit two different contributions to the resonance widths. We show that the parts of these widths, which vary from mode to mode, are associated to ohmic losses located at the boundary of the cavity. We also describe how this non-proportional damping is responsible for the complex character of wavefunctions (corresponding to a spatially non-uniform phase), which is ubiquitous in open or dissipative wave systems. We experimentally demonstrate that the non-proportional widths are related to a single parameter, which measures the amount of complexity of wavefunctions, and provide theoretical arguments in favor of this relation.