Disorder and temperature renormalization of interaction contribution to the conductivity in two-dimensional InxGa1-xAs electron systems

We study the electron-electron interaction contribution to the conductivity of two-dimensional In0.2Ga0.8As electron systems in the diffusion regime over the wide conductivity range sigma similar or equal to(1-50)G(0), where G(0) = e(2)/pi h. We show that the data are well described within the framework of the one-loop approximation of the renormalization-group (RG) theory when the conductivity is relatively high, sigma greater than or similar to 15G(0). At lower conductivity, the experimental results are found to be in drastic disagreement with the predictions of this theory. The theory predicts much stronger renormalization of the Landau's Fermi-liquid amplitude, which controls the interaction in the triplet channel, than that observed experimentally. A further contradiction is that the experimental value of the interaction contribution does not practically depend on the magnetic field, whereas the RG theory forecasts its strong decrease due to decreasing diagonal component of the conductivity tensor in the growing magnetic field.