Understanding transitions from FQAHS/FQH nematics to trivial gapless CDW phases

Clarify and characterize the transitions from the fractional quantum anomalous Hall plus smectic charge-density-wave (FQAHS) state, and from fractional quantum Hall nematic states, to topologically trivial gapless charge-density-wave phases such as the polar smectic metal, including the mechanisms by which topological order is lost.

Background

The integer Hall crystal to Wigner crystal transition is understood to occur via closing of the single-particle gap. In contrast, the nature of transitions from FQAHS and FQH nematic states to trivial gapless CDW phases is presently unclear.

This uncertainty spans whether these transitions are continuous or first-order in various regimes and what microscopic processes govern the loss of topological order.