An experimental device to break the reciprocity of acoustic wave propagation

Using an innovative acoustic transmission line, a team from the Institute of Electronics, Microelectronics and Nanotechnology has experimentally demonstrated the non-reciprocity of wave propagation in a medium whose properties are modulated in time and space. The results are published in the journal Applied Physics Letters.

Wave reciprocity can be defined as the invariance of measured signals when the source and receiver are swapped. However, this invariance can be broken in a transmission line whose properties are modulated in space and time. Until now, the difficulty of creating a sufficiently long transmission line and a sufficiently efficient and fast modulation had not allowed this phenomenon to be observed experimentally.