Switchable Chern insulator, isospin competitions and charge density waves in rhombohedral graphene moire superlattices
| Autor: | Zheng, Jian, Wu, Size, Liu, Kai, Lyu, Bosai, Liu, Shuhan, Sha, Yating, Li, Zhengxian, Watanabe, Kenji, Taniguchi, Takashi, Jia, Jinfeng, Shi, Zhiwen, Chen, Guorui |
|---|---|
| Rok vydání: | 2024 |
| Předmět: | |
| Druh dokumentu: | Working Paper |
| Popis: | Graphene-based moire superlattices provide a versatile platform for exploring novel correlated and topological electronic states, driven by enhanced Coulomb interactions within flat bands. The intrinsic tunability of graphene s multiple degrees of freedom enables precise control over these complex quantum phases. In this study, we observe a range of competing phases and their transitions in rhombohedrally stacked hexalayer graphene on hexagonal boron nitride (r-6G/hBN) moire superlattices. When electrons are polarized away from the moire superlattice, we firstly identify a Chern insulator with reversible Chern numbers at v = 1 (one electron per moire cell), attributed to the competition between bulk and edge magnetizations.Then, we detect transitions between three distinct insulating states at v = 2, driven by vertical displacement field D and vertical magnetic field B. These insulating phases are distinguished as spin-antiferromagnetic, spin-polarized, and valley-polarized insulators, based on their responses to parallel and perpendicular magnetic fields. When electrons are polarized toward the moire superlattice, in a device with large twist angle, insulating states appear at v = 1/3 and 2/3 at zero magnetic field, and v = 1/2 in a magnetic field. Our findings reveal a rich interplay of charge, isospin, topology and magnetic field in rhombohedral graphene moire superlattices. Comment: 24 pages, 10 figures |
| Databáze: | arXiv |
| Externí odkaz: |
|