Coalescence towards exceptional contours in synthetic phononic media
Department of Photonics Engineering, Technical University of Denmark - DK-2800 Kgs. Lyngby, Denmark
Received: 5 April 2016
Accepted: 30 May 2016
Parity-time symmetric media, also referred to as synthetic media, have been devised in many optical systems with the ground breaking potential to create non-reciprocal structures and one-way cloaks of invisibility. Here we demonstrate a feasible approach for the case of sound where gain and loss are induced via the acousto-electric effect in electrically biased piezoelectric semiconductors. We study how wave attenuation and amplification can be tuned, and when combined, can give rise to phononic synthetic media with unidirectional suppressed reflectance, a feature directly applicable to evading sonar detections.
PACS: 77.55.hf – ZnO / 77.65.Dq – Acoustoelectric effects and surface acoustic waves (SAW) in piezoelectrics / 11.30.Er – Charge conjugation, parity, time reversal, and other discrete symmetries
© EPLA, 2016