Two-subband magnetotransport in GaAs single quantum well with superlattice doping

Two-subband magnetotransport of quasi-2D electron gas in GaAs single quantum well with AlAs/GaAs superlattice doping has been studied at $T = 4.2$ K in magnetic fields $B < 2T$. It was demonstrated that application of negative gate voltage leads to transformation of studied two-subband electron system into the one-subband system. This transformation is accompanied by appearance of positive magnetoresistance. This behavior has been described by conventional model of classical positive magnetoresistance that takes into account elastic intersubband scattering of electrons. Combined analysis of classical positive magnetoresistance and quantum magneto-intersubband oscillations makes it possible to define the values of transport rates of intrasubband scattering and quantum rate of intersubband scattering.