Resistivity of the spin-polarized two-dimensional electron gas: scaling and width effect

We present results for the magnetoresistance of the two-dimensional electron gas at zero temperatures in a parallel magnetic field. The parallel field gives rise to a spin-polarized electron gas. At low density, the magnetoresistance is positive due to screening effects. For impurity scattering we discuss the density dependence of the magnetoresistance and the related scaling properties. Width effects of the electron gas on the magnetoresistance are described for impurity scattering and interface-roughness scattering.