1. Mapping twist-tuned multi-band topology in bilayer WSe$_2$
- Author
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Foutty, Benjamin A., Kometter, Carlos R., Devakul, Trithep, Reddy, Aidan P., Watanabe, Kenji, Taniguchi, Takashi, Fu, Liang, and Feldman, Benjamin E.
- Subjects
Condensed Matter - Strongly Correlated Electrons ,Condensed Matter - Mesoscale and Nanoscale Physics ,Strongly Correlated Electrons (cond-mat.str-el) ,Mesoscale and Nanoscale Physics (cond-mat.mes-hall) ,FOS: Physical sciences - 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, and despite numerous predictions of nontrivial topology in these homobilayers, experimental evidence has remained elusive. Here, we conduct local electronic compressibility measurements of twisted bilayer WSe$_2$ 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. Furthermore, by measuring at a variety of local twist angles, we characterize how the interacting ground states of the underlying honeycomb superlattice depend on the size of the 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.
- Published
- 2023
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