Abstract
We present a theoretical study of an interaction-driven quantum phase diagram of twisted bilayer at hole filling factor as a function of twist angle and layer potential difference , where is generated by an applied out-of-plane electric field. At , the phase diagram includes quantum anomalous Hall insulators in the intermediate regime and topologically trivial multiferroic states with coexisting ferroelectricity and magnetism in both small and large regimes. There can be two transitions from the quantum anomalous Hall insulator phase to topologically trivial out-of-plane ferromagnetic phase, and finally to in-plane antiferromagnetic phase as increases, or a single transition without the intervening ferromagnetic phase. We show explicitly that the spin vector chirality of various antiferromagnetic states can be electrically switched. We discuss the connection between the experimentally measured Curie-Weiss temperature and the low-temperature magnetic order based on an effective Heisenberg model with magnetic anisotropy.
- Received 4 October 2023
- Revised 2 January 2024
- Accepted 5 January 2024
DOI:https://doi.org/10.1103/PhysRevB.109.L041106
©2024 American Physical Society