Bilayer Coherent and Quantum Hall Phases: Duality and Quantum Disorder
  We consider a fully spin-polarized quantum Hall system with no interlayer tunneling at total filling factor $\nu=1/k$ (where $k$ is an odd integer) using the Chern-Simons-Ginzburg-Landau theory. Exploiting particle-vortex duality and the concept of quantum disordering, we find a large number of possible compressible and incompressible ground states, some of which may have relevance to recent experiments of Spielman {\it et.al.}. We find interlayer coherent compressible states without Hall quantization and interlayer-incoherent incompressible with Hall quantization in addition to the usual $(k,k,k)$ Halperin states, which are both interlayer-coherent and incompressible. 
Eugene Demler, Chetan Nayak, Sankar Das Sarma