Transmission in waveguides with compositional and structural disorder: experimental effects of disorder cross-correlations

TL;DR

This study investigates how cross-correlations between different types of disorder in a waveguide influence microwave transmission, confirming theoretical predictions and highlighting the importance of disorder correlations in finite systems.

Contribution

It provides experimental evidence on the effects of disorder cross-correlations on wave transmission, aligning with theoretical models and emphasizing their significance in small disordered samples.

Findings

Cross-correlations can enhance or suppress transmission gaps.

Experimental results match theoretical predictions from the Kronig-Penney model.

Disorder correlations significantly affect waveguide transmission in finite samples.

Abstract

We analyse the single-mode transmission of microwaves in a guide with internal random structure. The waveguide contains scatterers characterised by random heights and positions, corresponding to compositional and structural disorder. We measure the effects of cross-correlations between two kinds of disorder, showing how they enhance or attenuate the experimentally found transmission gaps generated by long-range self-correlations. The results agree with the theoretical predictions obtained for the aperiodic Kronig-Penney model and prove that self- and cross-correlations have relevant effects also in finite disordered samples of small size.