Magnetotransport in two-dimensional n-InGaAs∕GaAs double-quantum-well structures near the transition from the insulator to the quantum Hall effect regime

Abstract

The temperature and magnetic-field dependence of the components of the conductivity and resistivity tensors are calculated with the quantum corrections due to the weak localization effect and electron-electron interaction taken into account in the diffusion and ballistic regimes. The corrections to the conductivity from the weak localization and electron-electron interaction and also the influence of spin and oscillation effects are taken into account by a renormalization of the transport relaxation time of the electron momentum, with the result that the Drude conductivity becomes temperature dependent. A calculation of the components of the conductivity and resistivity tensors is carried out with the use of the theoretical values of the parameters of the theory of quantum corrections, which are determined solely by the values of the carrier density and mobility of a particular sample. The results of the calculation are compared with experimental results for two-dimensional n-InGaAs∕GaAs structures with double quantum wells. It is shown that taking only the quantum corrections into account with the theoretical values of the parameters does not permit even a qualitative description of experiment, and it is therefore necessary to take additional temperature-dependent contributions to the Drude conductivity into account.