Exciton crystal melting and destruction by disorder in a bilayer quantum Hall system with a total filling factor of one

A bilayer quantum Hall system with a total filling factor of one was studied in the regime of a heavy layer imbalance in a recent transport experiment (Y. Zeng et al., arXiv:2306.16995), with intriguing new findings. We demonstrate in this paper that (1) the exciton Wigner crystal in this regime can melt into a superfluid phase, giving rise to reentrant superfluid behavior; and (2) in the presence of disorder, electron and hole Wigner crystals in the two layers go through a locking-decoupling transition as the layer separation increases, resulting in a sudden change in the counterflow conductance. A comparison will be made with the findings of the experiments.