在一个磁拓绝缘器中,在零磁场下直接观察奇拉边缘电流
Jinjiang Zhu1, Yang Feng2, Xiaodong Zhou3,4,5
1State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai, China.
Nature communications
|January 22, 2025
概括
研究人员在MnBi2Te4中成像了奇拉边缘电流,这是一种理论上被认为是量子异常霍尔 (QAH) 绝缘体的材料. 这些电流证明了材料的材料.
科学领域:
- 凝聚物质物理学 凝聚物质物理学
- 材料科学 材料科学 材料科学
- 量子物理学 量子物理学 是一种量子物理学.
背景情况:
- 量子异常霍尔 (QAH) 绝缘体表现出奇拉边缘电流,这是它们拓性质的标志.
- 预计MnBi2Te4,一种抗铁磁范德瓦尔斯材料,在奇数层结构中承载QAH状态.
- 对于MnBi2Te4中的QAH状态的实验证据受到观察到的霍尔电阻在理论量子化值以下的限制.
研究的目的:
- 直接可视化和描述MnBi2Te4.4中性边缘电流.
- 为了研究这些边缘电流在各种条件下的行为,如封闭和磁化.
- 将实验观测与本材料中QAH状态的理论预测相协调.
主要方法:
- 使用扫描超导量子干扰装置 (sSQUID) 显微镜来图像电流分布.
- 将MnBi2Te4装置连接到它的中性电荷点,以优化边缘电流的观察.
- 在不同的磁场和磁化方向下进行测量.
主要成果:
- 在奇数层 MnBi2Te4.4 的边界上成功成像了单向的性边缘电流.
- 观察到边缘电流的奇拉性与散装磁化相反.
- 发现边缘通道尽管存在大量导电,但仍然存在,即使化学潜力处于带间隙内.
结论:
- 确立了在拓反铁磁体MnBi2Te4.4中存在性边缘电流的存在.
- 证明了这些边缘通道对大规模散射的强度.
- 提供了一种用于识别抗铁磁材料中的QAH状态的新方法.
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