Electric-Field Switchable Chirality in Rhombohedral Graphene Chern Insulators Stabilized by Tungsten Diselenide

Jing Ding; Hanxiao Xiang; Jiannan Hua; Wenqiang Zhou; Naitian Liu; Le Zhang; Na Xin; Bing Wu; Kenji Watanabe; Takashi Taniguchi; Zdeněk Sofer; Wei Zhu; Shuigang Xu

doi:10.1103/physrevx.15.011052

Article Electric-Field Switchable Chirality in Rhombohedral Graphene Chern Insulators Stabilized by Tungsten Diselenide

Jing Ding ; Hanxiao Xiang ; Jiannan Hua ; Wenqiang Zhou ; Naitian Liu ; Le Zhang ; Na Xin ; Bing Wu ; Kenji Watanabe (National Institute for Materials Science) ; Takashi Taniguchi (National Institute for Materials Science) ; Zdeněk Sofer ; Wei Zhu ; Shuigang Xu

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Jing Ding, Hanxiao Xiang, Jiannan Hua, Wenqiang Zhou, Naitian Liu, Le Zhang, Na Xin, Bing Wu, Kenji Watanabe, Takashi Taniguchi, Zdeněk Sofer, Wei Zhu, Shuigang Xu. Electric-Field Switchable Chirality in Rhombohedral Graphene Chern Insulators Stabilized by Tungsten Diselenide. Physical Review X. 2025, 15 (1), 011052. https://doi.org/10.1103/physrevx.15.011052

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Chern insulators host topologically protected chiral edge currents with quantized conductance characterized by their Chern number. Switching the chirality of a Chern insulator, namely, the direction of the edge current, is highly challenging due to topologically forbidden backscattering but is of considerable importance for the design of topological devices. Nevertheless, this can be achieved by reversing the sign of the Chern number. Here, we report electrically switchable chirality in rhombohedral multilayer graphene-based Chern insulators through a topological phase transition. By introducing moire ́ superlattices in rhombohedral heptalayer graphene, we observe a cascade of topological phase transitions at quarter electron filling of a moire ́ band with the Chern number tunable from −1, 1, to 2. Furthermore, integrating monolayer tungsten diselenide at the moire ́less interface of rhombohedral decalayer graphene and hexagonal boron nitride superlattices stabilizes the Chern insulators, enabling quantized anomalous Hall resistance of h=2e2. Remarkably, the Chern number can be electrically switched using displacement fields, leading to a topological phase transition from −1 to 2. Our work establishes rhombohedral multilayer graphene moire ́ superlattices as a versatile platform for topological engineering, with switchable chirality offering significant promise for integrating chiral edge currents into topological electronic circuits.

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