Strain Tunable Semimetal-Topological-Insulator Transition in Monolayer 1T '-WTe2
Strain Tunable Semimetal-Topological-Insulator Transition in Monolayer 1T '-WTe2
复制标题
单层 1T-2-WTe2 中应变可调谐半金属-拓扑-绝缘体转变
DOI：
10.1103/physrevlett.125.046801
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发表时间：
2020
影响因子：
8.6
通讯作者：
Jia Jinfeng
中科院分区：
文献类型：
--
作者：
Zhao Chenxiao;Hu Mengli;Qin Jin;Xia Bing;Liu Canhua;Wang Shiyong;Guan DanDan;Li Yaoyi;Zheng Hao;Liu Junwei;Jia Jinfeng
量子自旋霍尔绝缘体表现为其导电边缘通道，起源于绝缘体态的非平凡拓扑结构。单层在输运测量中表现出这种量化的边缘电导，但由于其半金属性质，相干长度被限制在100 nm左右。为了克服这一限制，我们提出了一种应变工程技术来调整电子结构，其中无论是压缩应变沿着轴或拉伸应变沿着轴可以驱动到一个完整的间隙绝缘相。分子束外延和原位扫描隧道显微镜或光谱学的联合研究证实了这种相变。同时，拓扑边缘状态被发现是非常强大的应变的存在。
A quantum spin hall insulator is manifested by its conducting edge channels that originate from the nontrivial topology of the insulating bulk states. Monolayerexhibits this quantized edge conductance in transport measurements, but because of its semimetallic nature, the coherence length is restricted to around 100 nm. To overcome this restriction, we propose a strain engineering technique to tune the electronic structure, where either a compressive strain along theaxis or a tensile strain along theaxis can driveinto an full gap insulating phase. A combined study of molecular beam epitaxy andin situscanning tunneling microscopy or spectroscopy then confirmed such a phase transition. Meanwhile, the topological edge states were found to be very robust in the presence of strain.