Fractional quantum Hall effect at half-filled Landau level in a multiple-layer electron system.

Abstract

We have studied the excitation spectrum for a one-half filled Landau level in a two-layer system of interacting electrons, by finite-size calculations in a periodic rectangular geometry. The interlayer interaction is found to be important for obtaining a unique ground state and the required gap structure in the spectrum. On the basis of these observations, we predict that the fractional quantum Hall effect might be found at this filling in such a layered system.