Residual interactions and correlations among Laughlin quasiparticles: novel hierarchy states

The residual interactions between Laughlin quasiparticles can be obtained from exact numerical diagonalization studies of small systems. The pseudopotentials VQP(R) describing the energy of interaction of QEʹs (or QHʹs) as a function of their ‘relative angular momentum’ R cannot support Laughlin correlations at certain QP filling factors (e.g., νQE=1/3 and νQH=1/5). Because of this the novel condensed quantum fluid states observed at ν=4/11, 4/13 and other filling fractions cannot possibly be spin polarized Laughlin correlated QP states of the composite Fermion hierarchy. Pairing of the QPʹs clearly must occur, but the exact nature of the incompressible ground states is not completely clear.