High-Chern-number and high-temperature quantum Hall effect without Landau levels

• 作者: Hao Li Jiaheng Li Jian Wang Jun Ge Tianchuang Luo Yang Wu Yanzhao Liu Yong Xu
• 来源期刊: 国家科学评论（英文版）
• 关键词: quantum Hall effect without Landau levels Chern insulator topological matter topological quantum states high Chern number high temperature
• 年，卷（期）: 2020,（8）
• 页码范围: 1280-1287
• 页数: 8页
• 语种: 英文
• DOI: 10.1093/nsr/nwaa089

摘要

The quantum Hall effect (QHE) with quantized Hall resistance of h/ve2 started the research on topological quantum states and laid the foundation of topology in physics.Since then,Haldane proposed the QHE without Landau levels,showing nonzero Chern number | C| =1,which has been experimentally observed at relatively low temperatures.For emerging physics and low-power-consumption electronics,the key issues are how to increase the working temperature and realize high Chern numbers (C ＞ 1).Here,we report the experimental discovery ofhigh-Chern-number QHE (C =2) without Landau levels and C =1 Chern insulator state displaying a nearly quantized Hall resistance plateau above the Néel temperature in MnBi2Te4 devices.Our observations provide a new perspective on topological matter and open new avenues for exploration of exotic topological quantum states and topological phase transitions at higher temperatures.