Acoustoelectric effect in strongly correlated oxides*

The acoustoelectric (AE) effect, which manifests itself as the generation of a DC current by a propagating acoustic wave, may convey crucial information on the interdependence between the structural and electronic properties of strongly correlated oxides. We observed that acoustic waves may be coupled not only to an electronic but also to a magnonic state of these materials. In this work, we studied the AE effect in non-magnetic (VO₂, V₂O₃) and ferromagnetic La_0.7Sr_0.3MnO₃ wires grown on top of piezoelectric LiNbO₃ substrates. It was observed that the resistance change across a metal-insulator transition results in a significant enhancement of the AE current in the vanadates wires. Additionally, we show that the sign of the AE current differs for excitations produced by bulk and surface acoustic waves. Importantly, it was observed that the AE current in the La_0.7Sr_0.3MnO₃ wire can be significantly tuned by applying an external magnetic field. Our work provides a new platform for surface acoustic wave devices based on Mott transitions.