Observation of Shapiro Steps in the Charge Density Wave State Induced by Strain on a Piezoelectric Substrate

Abstract: Recent development in nanotechnology has enabled us to investigate the dynamic properties of van der Waals materials on a piezoelectric substrate. Here we report on the dynamics of charge density wave (CDW) in NbSe${3}$ nanowires induced by surface acoustic waves (SAWs). Clear peaks in the differential resistance were observed at the resonant frequency of the SAW device. These peaks known as Shapiro steps are typically observed by applying an rf current to NbSe${3}$ nanowires. We found that the Shapiro steps induced by SAWs show several distinct features from the ones induced by an rf current. Our detailed study revealed that a strain induced by SAWs plays a significant role in the Shapiro steps. The result clearly demonstrates the importance of the strain in CDW materials and paves the way for strain-induced device applications.