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

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.