Impact of non-Hemiticity on modal strength and correlation in transmission through random open cavities

TL;DR

This study demonstrates how non-Hermiticity in open random systems enhances modal excitation and correlations, affecting wave transmission and speckle patterns, with implications for complex wave systems.

Contribution

It provides experimental evidence on how non-Hermiticity influences modal strength and correlations in open random cavities, a topic previously unexplored in microwave systems.

Findings

Modal transmission coefficients can reach values comparable to the dimensionless conductance.

Non-Hermiticity leads to strong correlation between modes and enhanced modal excitation.

Negative correlation between speckle patterns ensures net transmission does not exceed incident power.

Abstract

The nonorthogonality of eigenfunctions over the volume of non-Hermitian systems determines the nature of waves in complex systems. Here, we show in microwave measurements of the transmission matrix that the non-Hermiticity of open random systems leads to enhanced modal excitation and strong correlation between modes. Modal transmission coefficients reach values comparable to the dimensionless conductance which may be much larger than unity. This is accompanied by strong negative correlation between modal speckle patterns ensuring that net transmission is never larger than the incident power.