Effect of Frequency and Electric Modulation on the Resistivity of a 2D Electron Gas

We calculate the frequency-dependent quantum magnetotransport (QMT) coefficients of a two-dimensional electron gas (2DEG) with electrostatic modulation. A perpendicular magnetic field is applied and our calculations are carried out using the Kubo method. We obtain analytic expressions for the band part and impurity contributions to the longitudinal and transverse conductivity coefficients. We analyze the effect of the scattering potential and frequency on the QMT coefficients. Preliminary calculations show that at zero frequency, the scattering part of the longitudinal conductivity increases with the lattice scattering at low magnetic fields but decreases when the lattice potential is increased at large magnetic fields. The effect of finite frequency is to enhance the forward scattering significantly on the longitudinal conductivity at low magnetic fields when the scattering potential is weak. Detailed results will be presented for various values of the parameters.