Towards altering sound frequency at will by a linear meta-layer with time-varying and quantized properties

Abstract

Temporal modulation materials have been attracting attention thanks to their ability to break wave reciprocity, i.e., waves traveling from point A to B are identical to waves propagating from B to A. The authors present a linear temporal modulation device with a giant acoustic impedance modulation ratio and ability to linearly change wave frequency, operating in two quantized states when a shunt circuit is connected and disconnected by a MOSFET.