Density of states of electrons in weak random potential in two dimensions

Abstract

We study density of states of electrons in weak Gaussian potential model distributed randomly in the two dimensional system by the variational path integral method. The Fourier transform of Green function is separated into two parts, each part can be described as two dimensional systems with different energy range. We found the new variational method to combine two parts of the density of states with continuous and smooth slope. We observed that the frequency of the system from this method does not differ much from the other methods, and we also discussed the shifting of the Fermi-level by the impurity effect.