凝聚态物理
铁磁性
量子反常霍尔效应
居里温度
Dirac(视频压缩格式)
单层
物理
拓扑绝缘体
半金属
材料科学
带隙
量子霍尔效应
量子力学
纳米技术
电子
中微子
作者
Xiaoyu Xuan,Zhuhua Zhang,Changfeng Chen,Wanlin Guo
出处
期刊:Nano Letters
[American Chemical Society]
日期:2022-07-01
卷期号:22 (13): 5379-5384
被引量:13
标识
DOI:10.1021/acs.nanolett.2c01421
摘要
Quantum anomalous Hall (QAH) insulators possess exotic properties driven by novel topological physics, but related studies and potential applications have been hindered by the ultralow temperatures required to sustain the operating mechanisms dictated by key material parameters. Here, using first-principles calculations, we predict a robust QAH state in monolayer TiTe that exhibits a high ferromagnetic Curie temperature of 650 K and a sizable band gap of 261 meV. These outstanding benchmark properties stem from the Te atom's large size that favors ferromagnetic kinetic exchange with the neighboring Ti atoms and strong spin-orbit coupling that creates a QAH state by adding a mass term to the Dirac half-semimetal state. Remarkably, the ferromagnetic order remains robust against interlayer stacking via the d-pz/py-pz-d super-super exchange, generating unprecedented QAH states in few-layer configurations with enhanced Curie temperatures and higher Chern numbers. These results signify layered TiTe to be a prime template for exploring novel QAH physics at ambient and higher temperatures.
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