Phase competition of the ν=9/5 fractional quantum Hall state and the reentrant integer quantum Hall Wigner solid

In the two-dimensional electron gas fractional quantum Hall states and electron solids often compete. We recently observed such a competition near the Landau level filling factor ν=9/5. In this area we observed a Wigner-solid-like phase at a new filling factor ν=1.79. Because of the reentrant nature of the transport, we call this phase the reentrant integer quantum Hall Wigner solid. This Wigner solid develops in a range of Landau level filling factors that is related by particle-hole symmetry to the so-called reentrant Wigner solid that forms near ν=1/5. Thus, our finding of the integer quantum Hall Wigner solid underscores the pervasiveness of particle-hole symmetry in quantum Hall systems and further illustrates the delicate interplay of topological physics and strong Coulomb interactions.