量子异常的霍尔效应来自交织的莫尔带
Tingxin Li1,2, Shengwei Jiang1,2, Bowen Shen1
1School of Applied and Engineering Physics and Laboratory of Atomic and Solid State Physics, Cornell University, Ithaca, NY, USA.
Nature
|December 23, 2021
概括
研究人员观察到半导体moiré材料中的量子异常霍尔效应. 一个电场调整了拓和相关性,导致了新的拓相位过渡,而没有关闭散装电荷间隙.
科学领域:
- 凝聚物质物理
- 半导体物理
- 材料科学
背景情况:
- 电子相关性和波段拓是现代物理学的关键领域.
- 半导体moiré材料为研究电子相关现象提供了一个可调的平台.
- 这些系统中的非微不足道带拓在很大程度上仍未被探索.
研究的目的:
- 研究半导体摩尔材料中的电子相关性和带拓的相互作用.
- 探索像量子异常霍尔效应这样的拓现象的可能性.
- 了解电场诱导的拓相变.
主要方法:
- 用AB堆叠的MoTe2/WSe2摩尔异构体的制造和表征.
- 应用外平面电场来调整材料的特性.
- 在不同的条件下测量霍尔电阻和纵向电阻.
主要成果:
- 在AB堆叠的MoTe2/WSe2摩尔异构体中观察量子异常霍尔效应 (量子化霍尔电阻h/e^2).
- 证明电场控制带宽和带拓.
- 电场诱导的从Mott绝缘体到量子异常的Hall绝缘体的拓相过渡的识别,在绝缘体到金属过渡之前没有散装电荷间隙关闭.
结论:
- 半导体moiré异构体是探索相关拓状态的有希望的平台.
- 电场调节带拓为控制量子现象提供了新的途径.
- 观察到的相位过渡机制为由相关性和拓学驱动的新型拓学现象提供了洞察力.
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