Exploring re-entrant integer quantum hall phases in two-dimensional heterostructures

Fractional quantum Hall states are promising platforms for topological quantum computation. In particular, the fractional quantum hall effect (FQH) state at filling factor v=5/2 and v=7/2 are believed to exhibit non-Abelian quasiparticle statistics. GaAs/AlGaAs quantum wells with ultra-high mobilities are a well-established platform to probe these states through magneto-transport measurements. More recently electronic interferometers using quantum point contacts have emerged as a powerful technique to probe both the fractional charge and braiding statistics of these quasiparticles.

Within the filling factor range of 2 to 4 containing non-Abelian candidate states, integer re-entrant quantum Hall phases exist in filling factors that are in proximity to the non-Abelian fractional states. It is critical to understand the effects of these re-entrant phases in the same heterostructure designs, as are used in our interference measurements. In this work we explore the specific energy scales and morphologies of these phases in Hall bars fabricated from these high mobility GaAs quantum wells with different sheet electron densities.