New fractional quantum Hall state in double-layer two-dimensional electron systems

Abstract

Transport studies on bilayer two-dimensional electron systems in GaAs double quantum wells have revealed a new fractional quantum Hall state that has no known counterpart in a single-layer 2D system. At total filling fraction \ensuremath{\nu}=1/2 we observe a deep minimum in the diagonal resistivity and a flat Hall plateau within 1.5% of 2h/${\mathit{e}}^{2}$. Studies of this new state in several samples with varying densities and layer separations strongly suggest this new state arises from interlayer Coulomb correlations. The data also suggest that the \ensuremath{\nu}=1 quantum Hall effect seen in these samples has a similar origin.