We propose that quantum Hall bilayers in the presence of a periodic potential at the scale of the magnetic length can host examples of a deconfined metal-insulator transition (DMIT), where a Fermi-liquid (FL) metal with a generic electronic Fermi surface evolves into a gapped insulator (or an insulator with Goldstone modes) through a continuous quantum phase transition.The transition can be accessed by tuning a single parameter, and its universal critical properties can be understood using a controlled framework.At the transition, the two layers are effectively decoupled, where each layer undergoes a continuous transition from a FL to a generalized composite Fermi liquid (gCFL).The thermodynamic and transport properties of the gCFL are similar to the usual CFL, while its spectral properties are qualitatively different.The FL-gCFL quantum critical point hosts a sharply defined Fermi surface without long-lived electronic quasiparticles.Immediately across the transition, the two layers of gCFL are unstable to forming an insulating phase.We discuss the topological properties of the insulator and various observable signatures associated with the DMIT.We propose that quantum Hall bilayers in the presence of a periodic potential at the scale of the magnetic length can host examples of a deconfined metal-insulator transition (DMIT), where a Fermi-liquid (FL) metal with a generic electronic Fermi surface evolves into a gapped insulator (or an insulator with Goldstone modes) through a continuous quantum phase transition.The transition can be accessed by tuning a single parameter, and its universal critical properties can be understood using a controlled framework.At the transition, the two layers are effectively decoupled, where each layer undergoes a continuous transition from a FL to a generalized composite Fermi liquid (gCFL).The thermodynamic and transport properties of the gCFL are similar to the usual CFL, while its spectral properties are qualitatively different.The FL-gCFL quantum critical point hosts a sharply defined Fermi surface without long-lived electronic quasiparticles.Immediately across the transition, the two layers of gCFL are unstable to forming an insulating phase.We discuss the topological properties of the insulator and various observable signatures associated with the DMIT.

arXiv:2004.14391Physical Review ResearchSep 22, 202014 citations

Disorder-driven phase transitions in bosonic fractional quantum Hall liquids

Chao Han, Zhao Liu

We investigate the disorder-driven phase transitions in bosonic fractional quantum Hall liquids at filling factors $f=1/2$ and $f=1$ in the lowest Landau level. We use the evolution of ground-state entanglement entropy, fidelity susceptibility, and Hall conductance with increasing disorder strength to identify the underlying phase transitions. The critical disorder strengths obtained from these different quantities are consistent with each other, validating the reliability of our numerical calculations based on exact diagonalization. At $f=1/2$ , we observe a clear transition from the bosonic Laughlin state to a trivial insulating phase. At $f=1$ , we identify a direct phase transition from the non-Abelian bosonic Moore-Read state to a trivial insulating phase, although some signs of a disorder-induced intermediate fractional quantum Hall phase were recently reported for the $f=5/2$ fermionic cousin.We investigate the disorder-driven phase transitions in bosonic fractional quantum Hall liquids at filling factors $f=1/2$ and $f=1$ in the lowest Landau level. We use the evolution of ground-state entanglement entropy, fidelity susceptibility, and Hall conductance with increasing disorder strength to identify the underlying phase transitions. The critical disorder strengths obtained from these different quantities are consistent with each other, validating the reliability of our numerical calculations based on exact diagonalization. At $f=1/2$, we observe a clear transition from the bosonic Laughlin state to a trivial insulating phase. At $f=1$, we identify a direct phase transition from the non-Abelian bosonic Moore-Read state to a trivial insulating phase, although some signs of a disorder-induced intermediate fractional quantum Hall phase were recently reported for the $f=5/2$ fermionic cousin.

arXiv:2108.00972Physical review. B./Physical review. BJan 3, 20220 citations

We investigate the disorder-driven phase transitions in bosonic fractional quantum Hall liquids at filling factors

f=1/2

and

f=1

in the lowest Landau level. We use the evolution of ground-state entanglement entropy, fidelity susceptibility, and Hall conductance with increasing disorder strength to identify the underlying phase transitions. The critical disorder strengths obtained from these different quantities are consistent with each other, validating the reliability of our numerical calculations based on exact diagonalization. At

f=1/2

, we observe a clear transition from the bosonic Laughlin state to a trivial insulating phase. At

f=1

, we identify a direct phase transition from the non-Abelian bosonic Moore-Read state to a trivial insulating phase, although some signs of a disorder-induced intermediate fractional quantum Hall phase were recently reported for the

f=5/2

fermionic cousin.