Moiré-driven topological electronic crystals in twisted graphene

• 成果类型: Article
• 署名作者: Su, Ruiheng; Waters, Dacen; Zhou, Boran; Watanabe, Kenji; Taniguchi, Takashi; Zhang, Ya-Hui; Yankowitz, Matthew; Folk, Joshua
• 署名单位: University of British Columbia; University of British Columbia; University of Washington; University of Washington Seattle; University of Washington; University of Washington Seattle; Johns Hopkins University; National Institute for Materials Science; National Institute for Materials Science; University of Washington; University of Washington Seattle
• 刊物名称: Nature
• ISSN/ISSBN: 0028-3645
• DOI: 10.1038/s41586-024-08239-6
• 发表日期: 2025-01-30
• 关键词: fractional chern insulators; moir-and-eacute; hall; STATES

摘要

In a dilute two-dimensional electron gas, Coulomb interactions can stabilize the formation of a Wigner crystal1, 2-3. Although Wigner crystals are topologically trivial, it has been predicted that electrons in a partially filled band can break continuous translational symmetry and time-reversal symmetry spontaneously, resulting in a type of topological electron crystal known as an anomalous Hall crystal4, 5, 6, 7, 8, 9, 10-11. Here we report signatures of a generalized version of the anomalous Hall crystal in twisted bilayer-trilayer graphene, whose formation is driven by the moir & eacute; potential. The crystal forms at a band filling of one electron per four moir & eacute; unit cells (nu = 1/4) and quadruples the unit-cell area, coinciding with an integer quantum anomalous Hall effect. The Chern number of the state is exceptionally tunable, and it can be switched reversibly between +1 and -1 by electric and magnetic fields. Several other topological electronic crystals arise in a modest magnetic field, originating from nu = 1/3, 1/2, 2/3 and 3/2. The quantum geometry of the interaction-modified bands is likely to be very different from that of the original parent band, which enables possible future discoveries of correlation-driven topological phenomena.