We investigate the relationship of the spontaneously interlayer coherent “111” state of quantum Hall bilayers at total filling factor $\nu =1\mathrm{}$ to “mutual” composite fermions, in which vortices in one layer are bound to electrons in the other. Pairing of the mutual composite fermions leads to the low-energy properties of the 111 state, as we explicitly demonstrate using field-theoretic techniques. Interpreting this relationship as a mechanism for interlayer coherence leads naturally to two candidate states with nonquantized Hall conductance: the mutual composite Fermi liquid and an interlayer coherent charge e Wigner crystal. The experimental behavior of the interlayer tunneling conductance and resistivity tensors are discussed for these states.

• Received 14 September 2001

DOI:https://doi.org/10.1103/PhysRevB.66.155401