Conductance anisotropy of high-mobility, modulation-doped GaAs single quantum wells

The conductance in high-mobility and high-density, modulation-doped GaAs single quantum wells on View the MathML source substrates with thin spacer layers is strongly anisotropic with a 2–3 times higher mobility in the View the MathML source than that in the [110] direction. We show that the anisotropic scattering potential is strongly influenced by additional X-like electrons in the barriers formed by short-period superlattices. The X-electrons are able to considerably smooth the fluctuations of the potential; thus, increasing the correlation length of the fluctuations. We investigate the correlation length of the potential fluctuations by oscillations in the low-field magnetoresistance.