OBSERVATION OF A REENTRANT INSULATING PHASE NEAR THE 1/3 FRACTIONAL QUANTUM HALL LIQUID IN A 2-DIMENSIONAL HOLE SYSTEM

In a dilute, low-disorder, two-dimensional hole system at the GaAs/AlGaAs heterointerface, we observe a reentrant insulating behavior around the nu = 1/3 fractional quantum Hall liquid at B congruent-to 5 T, strikingly similar to recent observations in low-disorder 2D electron systems near nu = 1/5. We interpret this behavior as manifesting a weakly pinned hole Wigner crystal around nu = 1/3, and suggest that its observation at such large-nu is a result of Landau-level mixing which, in the case of much heavier boles, significantly modifies the ground-state energies of the fractional quantum Hall and Wigner crystal states of the system.