Two-Parameter Scaling of Microwave Rectification vs Microwave Power at the Boundary between Two-Dimensional Electron Systems

摘要

We report measurements of the rectification of microwave radiation (0.7-20GHz) at the boundary between two-dimensional electron systems separated by anarrow gap on a silicon surface for different temperatures, electron densitiesand microwave power. For frequencies above 4 GHz and different temperatures,the rectified voltage V_{dc} as a function of microwave power P can be scaledonto a single universal curve V*_{dc}=f*(P*). The scaled voltage is a linearfunction of power, V*_{dc} ~ P* for small power and proportional to P*^{1/2} athigher power. A theory is proposed that attributes the rectification to thethermoelectric response due to strong local overheating by the microwaveradiation at the boundary between two dissimilar 2D metals. Excellent agreementis obtained between theory and experiment.