Abstract

We investigate the reentrant integer quantum anomalous Hall (RIQAH) states reported in twisted bilayer MoTe₂ and argue that the discrepancy between Hall conductivity measured via transport and that inferred from the Streda formula can be explained if the RIQAH state is a quantum Hall bubble or Wigner crystal phase, analogous to reentrant integer quantum Hall phases in GaAs quantum wells. The RIQAH state at filling ν = -0.63 is consistent with this picture, while the ν = -0.7 state likely requires a different explanation because its smaller apparent slope may be masked by a nearby resistive peak. We propose that this peak signals a phase transition near ν = -0.75, possibly driven by a van Hove singularity, implying a change in Fermi-surface topology and a nearby metallic phase with nonquantized Hall response.

Abstract

We investigate the reentrant integer quantum anomalous Hall (RIQAH) states reported in twisted bilayer MoTe₂ and argue that the discrepancy between Hall conductivity measured via transport and that inferred from the Streda formula can be explained if the RIQAH state is a quantum Hall bubble or Wigner crystal phase, analogous to reentrant integer quantum Hall phases in GaAs quantum wells. The RIQAH state at filling ν = -0.63 is consistent with this picture, while the ν = -0.7 state likely requires a different explanation because its smaller apparent slope may be masked by a nearby resistive peak. We propose that this peak signals a phase transition near ν = -0.75, possibly driven by a van Hove singularity, implying a change in Fermi-surface topology and a nearby metallic phase with nonquantized Hall response.

Abstract

We investigate the reentrant integer quantum anomalous Hall (RIQAH) states reported in twisted bilayer MoTe₂ and argue that the discrepancy between Hall conductivity measured via transport and that inferred from the Streda formula can be explained if the RIQAH state is a quantum Hall bubble or Wigner crystal phase, analogous to reentrant integer quantum Hall phases in GaAs quantum wells. The RIQAH state at filling ν = -0.63 is consistent with this picture, while the ν = -0.7 state likely requires a different explanation because its smaller apparent slope may be masked by a nearby resistive peak. We propose that this peak signals a phase transition near ν = -0.75, possibly driven by a van Hove singularity, implying a change in Fermi-surface topology and a nearby metallic phase with nonquantized Hall response.

Abstract

We investigate the reentrant integer quantum anomalous Hall (RIQAH) states reported in twisted bilayer MoTe₂ and argue that the discrepancy between Hall conductivity measured via transport and that inferred from the Streda formula can be explained if the RIQAH state is a quantum Hall bubble or Wigner crystal phase, analogous to reentrant integer quantum Hall phases in GaAs quantum wells. The RIQAH state at filling ν = -0.63 is consistent with this picture, while the ν = -0.7 state likely requires a different explanation because its smaller apparent slope may be masked by a nearby resistive peak. We propose that this peak signals a phase transition near ν = -0.75, possibly driven by a van Hove singularity, implying a change in Fermi-surface topology and a nearby metallic phase with nonquantized Hall response.