Coulomb drag in quantum Hall systems near v = 1/2

Abstract

We use the composite fermion approach for theoretical studies of the Coulomb drag between two parallel layers of two-dimensional electron gases in the quantum Hall regime near Landau level filling fraction v = 1/2. Within the composite fermion approach, we use Boltzmann transport theory to determine the polarizability of the composite fermions. While this approach works at filling fraction v = 1/2, a straight-forward expansion of the solution of the Boltzmann equation around v = 1/2 results in spurious divergences that stem from inaccuracies in the expansion at long wavelength. We then attempt to find expressions for the polarizability that are more accurate in this long wavelength limit. The excitation spectrum of the system in the absence of scattering consists of a discrete spectrum of 6 function poles. We introduce tools to deal with such expressions, but we find that we cannot yield any exact results from this approach due to complications in determining the location of poles and the resulting residues.