- Letter
Orbital Chern insulator at in twisted
Phys. Rev. B 109, L041403 – Published 10 January, 2024
DOI: https://doi.org/10.1103/PhysRevB.109.L041403
Abstract
In twisted , the latest transport measurement has reported observation of the quantum anomalous Hall effect at hole filling , which undergoes a topological phase transition to a trivial ferromagnet as layer hybridization gets suppressed by interlayer bias . Here we show that this underlies the existence of an orbital Chern insulating state with gate () switchable sign in an antiferromagnetic spin background at hole filling . From momentum-space Hartree-Fock calculations, we find this state has a topological phase diagram complementary to that of the one: by sweeping from negative to positive, the Chern number of this state can be switched between , 0, and , accompanied by a sign change of a sizable orbital magnetization. In the range of where this antiferromagnet is the ground state, the orbital magnetization allows magnetic field initialization of the spin antiferromagnetic order and the Chern number.