English

Apparent inconsistency between Streda formula and Hall conductivity in reentrant integer quantum anomalous Hall effect in twisted MoTe$_2$

Strongly Correlated Electrons 2025-12-24 v4 Mesoscale and Nanoscale Physics

Abstract

Recent experiments in twisted bilayer MoTe2_2 (tMoTe2_2) have uncovered a rich landscape of correlated phases. In this work, we investigate the reentrant integer quantum anomalous Hall (RIQAH) states reported by F. Xu, arXiv.2504.06972 which display a notable mismatch between the Hall conductivity measured via transport and that inferred from the Streda formula. We argue that this discrepancy can be explained if the RIQAH state is a quantum Hall bubble or Wigner crystal phase, analogous to similar well-established phenomena in two-dimensional (2D) GaAs quantum wells. While this explains the RIQAH state at filling ν=0.63\nu = -0.63, F. Xu et al. report that the other RIQAH state at ν=0.7\nu = -0.7 has a smaller slope, necessitating a different interpretation. We propose and substantiate with analysis of the experimental data that this discrepancy arises due to a nearby resistive peak masking the true slope. Furthermore, we identify this resistive peak as a signature of a phase transition near ν=0.75\nu = -0.75, possibly driven by a van Hove singularity. The anomalous Hall response and Landau fan evolution across this transition suggest a change in Fermi-surface topology and a metallic phase with a non quantized Hall response. These observations offer new insights into the nature of the RIQAH states and raise the possibility that the nearby superconducting phase may have a valley-imbalanced metal parent state.

Keywords

Cite

@article{arxiv.2506.10965,
  title  = {Apparent inconsistency between Streda formula and Hall conductivity in reentrant integer quantum anomalous Hall effect in twisted MoTe$_2$},
  author = {Yi Huang and Seth Musser and Jihang Zhu and Yang-Zhi Chou and Sankar Das Sarma},
  journal= {arXiv preprint arXiv:2506.10965},
  year   = {2025}
}

Comments

8 pages, 3 figures; updated upon journal acceptance