5 papers
Direct experimental observation of total absorption and loss compensation using sound waves with complex frequencies
Anis Maddi, Gaelle Poignand, Vassos Achilleos +2
In this study, we experimentally investigate the application of a transient signal with complex frequencies to the absorption and transmission of sound waves. Indeed, the emission…
Robustness of perfect transmission resonances to asymmetric perturbation
Ioannis Kiorpelidis, Panayotis Kalozoumis, Georgios Theocharis +3
We investigate the impact of asymmetric perturbations on the perfect transmission resonances (PTRs) of one-dimensional finite periodic systems. With no perturbations, the scatterin…
A nonreciprocal and tunable active acoustic scatterer
Anis Maddi, Gaelle Poignand, Vassos Achilleos +2
A passive loudspeaker mounted in a duct acts as a reciprocal scatterer for plane waves impinging on either of its sides. However, the reciprocity can be broken by means of an asymm…
Topologically invisible defects in chiral mirror lattices
Antonin Coutant, Li-Yang Zheng, Vassos Achilleos +3
One of the hallmark of topological insulators is having conductivity properties that are unaffected by the possible presence of defects. In this work, we go beyond backscattering i…
Transient amplification in stable Floquet media
Ioannis Kiorpelidis, Fotios K. Diakonos, Georgios Theocharis +1
The Mathieu equation occurs naturally in the description of vibrations or in the propagation of waves in media with time-periodic refractive index. It is known to lead to exponenti…