Electron transport in coupled quantum wells with double-Sided doping

The conductivity and Hall mobility have been measured in heterostructures with coupled quantum wells (QW) as functions of temperature and the QW width. If a tunnel-transparent barrier is inserted in the middle of a QW, the mobility increases in narrow wells and decreases in wide wells. The experimental data have been compared with the calculated dependences. It has been shown that the number of filled quantum-well subbands depends on the well width and the presence of a barrier. The magnetoresistance and Hall resistance were measured at a temperature of 4.2 K in the range of magnetic fields of 1–40 T. The filling of subbands was determined from a Fourier analysis of the Shubnikov-de Haas oscillations, and good agreement with the calculated data was obtained.