Numerical Kubo formula study of frictional drag in the integer quantum Hall regime

We study interlayer factional drag between two-dimensional electron systems in the strong magnetic field limit by evaluating the weak-coupling Kubo formula for interlayer drag numerically. The key quantity in this theory is the disorder averaged "triangle function", a product of three Greens functions of electrons that represents the dc current response of electrons in one layer to charge fluctuations in a remote current-carrying layer. We find that the disorder averaged triangle functions are proportional to the momentum transfer q→ at small |q→| and that they change sign under a ν → 1 - ν particle-hole transformations, vanishing for half-filled Landau levels.