在扭曲的双双层石墨烯中使用对称性破碎的芯片绝缘体
Minhao He1, Jiaqi Cai1, Ya-Hui Zhang2
1Department of Physics, University of Washington, Seattle, Washington 98195, United States.
Nano letters
|November 20, 2023
概括
扭曲双层石墨烯 (tDBG) 揭示了相关和拓状态的层次结构. 一个新型的折叠对称性切尔恩绝缘体 (SBCI) 状态在最佳扭转角度附近出现,显示自发的时间逆转对称性破坏.
科学领域:
- 凝聚物质物理学 凝聚物质物理学
- 材料科学是一种材料科学.
- 量子现象是一种量子现象.
背景情况:
- 扭曲双层石墨烯 (tDBG) 是一种可调的平台,用于探索强烈相关的和拓的电子状态.
- 在tDBG中的平面带可以通过位移场和扭曲角度进行调制,从而能够精确控制材料特性.
研究的目的:
- 构建一个全面的相位图的相关和拓状态在tDBG.
- 识别和描述新的电子状态作为扭曲角度和位移场的函数.
主要方法:
- 超过十几个tDBG设备的制造和电气测量.
- 扭转角度和垂直移位场的系统变化.
- 对称性破裂状态的分析,包括切尔恩绝缘体.
主要成果:
- 随着扭曲角度接近大约1.34°,出现了一个对称性破裂状态的层次结构.
- 发现了在7/2带填充时的切恩绝缘体 (SBCI) 状态和在11/3填充时的初始SBCI状态.
- 在SBCI状态中,在零场时观察异常的霍尔效应,表明自发的时间逆转对称性破坏.
结论:
- 阶段图揭示了tDBG中相关和拓现象的丰富景观.
- SBCI状态代表了一个重要的发现,对理解moiré系统中自发的对称性破坏有意义.
- 观察到的零场异常霍尔效应表明了新型自旋电子应用和莫雷超级晶格物理学的潜力.
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