Peculiar nonlinear depletion in double-layered gated Si-δ-doped GaAs

The low temperature measurement for the Hall effect of the two-dimensional electron system in a double-layered gated Si-δ-doped GaAs was presented. The complex peculiar nonlinear dependence of depletion on gate voltage was observed. The nonlinearity was explained on the basis of the assumption that the double-capacity model consists of two δ-doped two-dimensional electron layers and a metallic gate. The experimental results show that the electron mobility is linear with the electron density on a log-log scale.