WIGNER SOLID FROM FINITE-CLUSTER STUDIES

We perform finite-cluster exact diagonalization studies for electrons in the lowest Landau level for filling factors from 1/3 to 1/11. In contrast to previous studies, we focus on the ground-state eigenfunction. This wave function changes continuously for filling factors from 1/3 to 1/9. At a filling factor of 1/11, there is a dramatic qualitative change in the ground-state wave function. Associated with this change is a peak in the structure factor at a finite wave vector as well as excitation energies that are consistent with gapless excitations at 1/11 filling. These results are consistent with recent experimental findings.