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arXiv · 2304.09808

Mapping twist-tuned multiband topology in bilayer WSe$_2$

Benjamin A. Foutty·Carlos R. Kometter·Trithep Devakul·Aidan P. Reddy·Kenji Watanabe·Takashi Taniguchi·Liang Fu·Benjamin E. Feldman
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Abstract

Semiconductor moir\'e superlattices have been shown to host a wide array of interaction-driven ground states. However, twisted homobilayers have been difficult to study in the limit of large moir\'e wavelength, where interactions are most dominant. Here, we conduct local electronic compressibility measurements of twisted bilayer WSe$_2$ (tWSe$_2$) at small twist angles. We demonstrate multiple topological bands which host a series of Chern insulators at zero magnetic field near a 'magic angle' around $1.23^\circ$. Using a locally applied electric field, we induce a topological quantum phase transition at one hole per moir\'e unit cell. Our work establishes the topological phase diagram of a generalized Kane-Mele-Hubbard model in tWSe$_2$, demonstrating a tunable platform for strongly correlated topological phases.

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Benjamin A. Foutty, Carlos R. Kometter, Trithep Devakul, Aidan P. Reddy, Kenji Watanabe, Takashi Taniguchi, Liang Fu, Benjamin E. Feldman. 2023-04-19. Mapping twist-tuned multiband topology in bilayer WSe$_2$. https://doi.org/10.1126/science.adi4728

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