The Study Of Acoustoelectric Current Produced By Electron Transport In Quasi-One-Dimensional System

The study of electron transport in mesoscopic systems has recently attracted much attention. Some new phenomena have been found in the experiment about mesoscopic systems. In 1996, the group Pepper of Cavendish Laboratory not only observed the giant oscillation in the acoustoelectric current induced by the surface acoustic wave (SAW) as function of the split gate voltage when SAW launched along the quasi-one-dimensional electron channel defined in a GaAs/AlxGa1-xAs heterostructure by split gate but also found that the acoustoelectric current I versus the split gate voltage displayed a step-like behavior and the values of the current on the plateaus are quantized with , where is electron charge, is the SAW frequency, and is the number of electrons captured in the quantum well when the quasi-one-dimensional channel was pinched off. This observation not only has great significance on the theory of mesoscopic transport but also may afford an accurate standard of current. The realization of a standard of current is important because it would close the "metrological triangle" of resistance, voltage and current measurements or could alternatively be used to obtain a measure of the charge of an electron.The electron transport in a quasi-one-dimensional channel defined in a GaAs/AlxGa1-xAs heterostructure by split gate could be considered as the electron ballistic transport. Using the WKB approximation, we calculated the acoustoelectric current when only one electron was captured in the quantum well and discussed the effect on the acoustoelectric current caused by SAW power, SAW frequency, split gate voltage and Source-Drain bias. Based on this result, we considered the case when two interacting electrons were captured in the quantum well and analyzed the effect on the acoustoelectric current caused by the Coulomb interaction between electrons in the quantum well and Source-Drain bias.