Self-Consistent Treatment of Dynamical Diffusion Coefficient of Two Dimensional Random Electron System under Strong Magnetic Fields. II

On the assumption that the Landau subband splitting is much larger than the subband width, the dynamical diffusion coefficient D (ω, E ) of a two dimensional electron system scattered by randomly distributed short-ranged impurities under strong magnetic fields is determined through diagramatic self-consistent treatment. The case where the Fermi energy E lies within the N-th Landau subband with N =0 is considered. Essential features of D (ω, E ) are the same as in the case with N =0 which was discussed in the previous work. The quantity D (0, E ) is finite only when the Fermi energy E is equal to E N (the “subband center”) at which the real part of the Green function for the N -th subband becomes zero, i.e., all the states are localized except for those at the subband center. The N -dependence of D (0, E N ) and the N - and E -dependences of the localization length for E ≠ E N are discussed.