Tunable exceptional point and unidirectional zero reflection of a metabeam using shunted piezos

Abstract

Exceptional point transmissions and similarly interesting phenomena have recently found broad interest in photonics and acoustics. This is mainly for parity-time symmetric systems, which mostly need external energy. Yet, some attention has been paid to the exceptional points (EPs) in passive beams, but the necessary loss is difficult to engineer. Here, we propose a resonator-based metabeam with shunted piezos that shows EPs and unidirectional zero reflection of flexural waves. For this system, the EPs are conveniently tuned using a shunting resistance and negative capacitance, the latter thought to be an impossibility until just recently. The proposed design can be quite useful in non-destructive testing and structural health monitoring where there is a need to control reflected flexural waves.