Radio-frequency reflectometry—A fast and sensitive measurement method for two-dimensional systems

Abstract

We have used radio-frequency (rf) reflectometry for sensitive, large bandwidth measurements of two-dimensional (2D) systems in AlGaAs/GaAs heterostructures at millikelvin temperatures. We show that the sample geometry is important in explaining the rf response of the circuit. Our simple lumped element model, where the gated 2D system is described as a resistive transmission line, qualitatively agrees with the experimental findings.