Exceptional points and skin modes in non-Hermitian elastic phononic beams
Résumé
Exceptional points and skin effect are two hallmarks of non-Hermitian systems combining gain and loss. We demonstrate these phenomena for flexural waves in phononic beams based on applied forces with feedback control. The non-Hermiticity is realized either by means of applying piezoelectric patches on top of the beam or by using a periodic beam made of piezoelectric materials operating as sensor and actuator. We highlight the applications of exceptional points for enhanced sensitivity and of skin modes for energy harvesting.