Quantum transport in δ-doped quantum wells

The multisubband electron-transport properties are studied for GaAs/${\mathrm{Al}}_{\mathrm{x}}$${\mathrm{Ga}}_{1\mathrm{-}\mathrm{x}}$As quantum wells in which a thin doping layer is located in the center. The subband transport mobility and quantum mobility are obtained as a function of the width of the quantum well and doping concentration. The effects of the screening and the intersubband interaction are investigated through the control of the number of the occupied subbands by adjusting the width of the quantum well and are shown to be relevant in the multisubband transport of the present system. The subband quantum mobility is enhanced significantly due to the occupation of the next higher subband. We found that the dependence of the transport and the quantum mobility of each subband on the well width and doping concentration exhibits nonmonotonic behavior with the appearance of a local maximum.