MAGNETOTRANSPORT STUDY OF THE INTERSUBBAND SCATTERING IN AN SI DELTA-DOPED GAAS

The magneto-transport of an FET with a channel of an Si delta-doped Ga As layer is studied at 4.2 K to reveal the transport properties in the subband structure. The Shubnikov-de Haas effect is analysed as a func tion of the gate bias voltage to estimate the variation of the electro n density as well as the mobility in each subband. It is found that th e carrier density decreases linearly as a function of the gate voltage . The electron mobility in a given subband shows however an anomalous nonlinear decrease, which is attributed to intersubband scattering.