Phases of the multiple quantum well in a strong magnetic field: Possibility of irrational charge

We have constructed the phase diagram for a multiple-quantum-well system of two-dimensional electron layers in a strong perpendicular magnetic field. There are a number of different phases which appear as in-layer density and layer separation are varied. At densities corresponding to low filling factors of the lowest Landau level there are solid phases, while at higher densities a sequence of Laughlin-liquid-like states occurs at small layer separation. The excitations of the liquid states can exhibit irrational charge.