Fermi hypernetted-chain study of half-filled Landau levels with broken rotational symmetry

We investigate broken rotational symmetry ~BRS! states at half-filling of the valence Landau level ~LL!. We generalize Rezayi and Read’s ~RR! trial wave function, a special case of Jain’s composite fermion ~CF! wave functions, to include anisotropic coupling of the flux quanta to electrons, thus generating a nematic order in the underlying CF liquid. Using the Fermi hypernetted-chain method, which readily gives results in the thermodynamic limit, we determine the properties of these states in detail. By using the anisotropic pair distribution and static structure functions we determine the correlation energy and find that, as expected, RR’s state is stable in the lowest LL, whereas BRS states may occur at half-filling of higher LL’s, with a possible connection to the recently discovered quantum Hall liquid crystals.