Local probe of bulk and edge states in a fractional Chern insulator

• 成果类型: Article
• 署名作者: Ji, Zhurun; Park, Heonjoon; Barber, Mark E.; Hu, Chaowei; Watanabe, Kenji; Taniguchi, Takashi; Chu, Jiun-Haw; Xu, Xiaodong; Shen, Zhi-Xun
• 署名单位: Stanford University; Stanford University; Stanford University; United States Department of Energy (DOE); SLAC National Accelerator Laboratory; University of Washington; University of Washington Seattle; National Institute for Materials Science; National Institute for Materials Science; University of Washington; University of Washington Seattle; Stanford University
• 刊物名称: Nature
• ISSN/ISSBN: 0028-3665
• DOI: 10.1038/s41586-024-08092-7
• 发表日期: 2024-11-21
• 关键词: heterojunction solar-cells; sih3 radicals; quantum; statistics; EFFICIENCY; surface; adsorption; simulation; diffusion; hydrogen

摘要

The fractional quantum Hall effect is a key example of topological quantum many-body phenomena, arising from the interplay between strong electron correlation, topological order and time-reversal symmetry breaking. Recently, a lattice analogue of the fractional quantum Hall effect at zero magnetic field has been observed, confirming the existence of a zero-field fractional Chern insulator (FCI). Despite this, the bulk-edge correspondence-a hallmark of a FCI featuring an insulating bulk with conductive edges-has not been directly observed. In fact, this correspondence has not been visualized in any system for fractional states owing to experimental challenges. Here we report the imaging of FCI edge states in twisted MoTe2 (t-MoTe2) using microwave impedance microscopy1. By tuning the carrier density, we observe the system evolving between metallic and FCI states, the latter of which exhibits insulating bulk and conductive edges, as expected from the bulk-boundary correspondence. Further analysis suggests the composite nature of the FCI edge states. We also observe the evolution of edge states across the topological phase transition as a function of interlayer electric field and reveal exciting prospects of neighbouring domains with different fractional orders. These findings pave the way for research into topologically protected one-dimensional interfaces between various anyonic states at zero magnetic field, such as gapped one-dimensional symmetry-protected phases with non-zero topological entanglement entropy, Halperin-Laughlin interfaces and the creation of non-abelian anyons. The bulk-edge correspondence is directly imaged in a fractional Chern insulator at zero magnetic field with exciton-resonant microwave impedance microscopy, revealing spatially resolved bulk and edge characteristics, and the evolution of topological states in twisted MoTe2.