Electrically tuned topology and magnetism in twisted bilayer <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msub><mml:mi>MoTe</mml:mi><mml:mn>2</mml:mn></mml:msub></mml:math> at <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msub><mml:mi>ν</mml:mi><mml:mi>h</mml:mi></mml:msub><mml:mo>=</mml:mo><mml:mn>1</mml:mn></mml:mrow></mml:math>
Bohao Li, Wen-Xuan Qiu, Fengcheng Wu
Abstract
We present a theoretical study of an interaction-driven quantum phase diagram of twisted bilayer ${\mathrm{MoTe}}_{2}$ at hole filling factor ${\ensuremath{\nu}}_{h}=1$ as a function of twist angle $\ensuremath{\theta}$ and layer potential difference ${V}_{z}$, where ${V}_{z}$ is generated by an applied out-of-plane electric field. At ${V}_{z}=0$, the phase diagram includes quantum anomalous Hall insulators in the intermediate $\ensuremath{\theta}$ regime and topologically trivial multiferroic states with coexisting ferroelectricity and magnetism in both small and large $\ensuremath{\theta}$ 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 ${120}^{\ensuremath{\circ}}$ antiferromagnetic phase as $|{V}_{z}|$ increases, or a single transition without the intervening ferromagnetic phase. We show explicitly that the spin vector chirality of various ${120}^{\ensuremath{\circ}}$ 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.