Interlayer Coherent Composite Fermi Liquid Phase in Quantum Hall Bilayers

Abstract

We introduce an interlayer coherent composite Fermi liquid for ν=1/2+1/2 bilayers, in which interlayer Coulomb repulsion drives exciton condensation of composite fermions. As a result, composite fermions propagate coherently between layers—even though electrons do not—and form bonding and antibonding Fermi seas. This phase is compressible with respect to symmetric currents but quantum Hall-like in the counterflow channel. Quantum oscillations of the composite Fermi seas generate a new series of incompressible states at ν=p/[2(p±1)] per layer (p an integer), which is a bilayer analogue of Jain’s sequence.