Structures for interacting composite fermions: Stripes, bubbles, and fractional quantum Hall effect

Much of the present day qualitative phenomenology of the fractional quantum Hall effect can be understood by neglecting the interactions between composite fermions altogether. For example, the fractional quantum Hall effect at n5n/(2pn61) corresponds to filled composite-fermion Landau levels, and the compressible state at n51/2p to the Fermi sea of composite fermions. Away from these filling factors, the residual interactions between composite fermions will determine the nature of the ground state. In this paper, a model is constructed for the residual interaction between composite fermions, and various possible states are considered in a variational approach. Our study suggests the formation of composite-fermion stripes, bubble crystals, as well as fractional quantum Hall states for appropriate situations.