High-temperature quantum valley Hall effect with quantized resistance and a topological switch

• 成果类型: Article
• 署名作者: Huang, Ke; Fu, Hailong; Watanabe, Kenji; Taniguchi, Takashi; Zhu, Jun
• 署名单位: Pennsylvania Commonwealth System of Higher Education (PCSHE); Pennsylvania State University; Pennsylvania State University - University Park; National Institute for Materials Science; National Institute for Materials Science; Pennsylvania Commonwealth System of Higher Education (PCSHE); Pennsylvania State University; Pennsylvania State University - University Park; Zhejiang University
• 刊物名称: SCIENCE
• ISSN/ISSBN: 0036-10765
• DOI: 10.1126/science.adj3742
• 发表日期: 2024-08-09
• 页码: 657-661
• 关键词: graphene; state; superconductivity; transport

摘要

Edge states of a topological insulator can be used to explore fundamental science emerging at the interface of low dimensionality and topology. Achieving a robust conductance quantization, however, has proven challenging for helical edge states. In this work, we show wide resistance plateaus in kink states-a manifestation of the quantum valley Hall effect in Bernal bilayer graphene-quantized to the predicted value at zero magnetic field. The plateau resistance has a very weak temperature dependence up to 50 kelvin and is flat within a dc bias window of tens of millivolts. We demonstrate the electrical operation of a topology-controlled switch with an on/off ratio of 200. These results demonstrate the robustness and tunability of the kink states and its promise in constructing electron quantum optics devices.