Unconventional Fractional Quantum Hall States in a Wide Quantum Well

A bilayer electron system that is formed in a 60-nm-wide GaAs quantum well and has large difference of the densities layers been studied. It found that, when magnetic field tilted from normal to plane system, integer Hall effect states at filling factors Landau levels 1 2 disappear; instead, fractional interval between these appear ν F = 4/3, 10/7, 6/5 with odd denominators factor 5/4. Several different can be observed under variation field. The detected are interpreted as combined same layer higher density – lower density. These because redistribution electrons layers, which occurs appearance state 5/4 even denominator presumably attributed dominance interlayer electron–electron interaction over intralayer one for