Surface-acoustic-wave-induced AC–DC conversion in high- superconducting films

In a thin film of superconducting YBa2Cu3O7a surface acoustic wave (SAW) induces a DC voltage-drop close to the superconducting transition. While this effect is often ascribed to the acoustoelectric effect, the signal is shown to be composed of two parts: a component due to SAW-induced vortex-drag and a component that is related to harmonic interference effects.