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arXiv · 2009.11472

Strain Tunable Semimetal-Topological-Insulator Transition in Monolayer 1T'-WTe2

Chenxiao Zhao·Mengli Hu·Jin Qin·Bing Xia·Canhua Liu·Shiyong Wang·Dandan Guan·Yaoyi Li·Hao Zheng·Junwei Liu·Jinfeng Jia
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Abstract

A quantum spin hall insulator(QSHI) is manifested by its conducting edge channels that originate from the nontrivial topology of the insulating bulk states. Monolayer 1T'-WTe2 exhibits 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 a axis or a tensile strain along b axis can drive 1T'-WTe2 into an full gap insulating phase. A combined study of molecular beam epitaxy and in-situ scanning tunneling microscopy/spectroscopy then confirmed such a phase transition. Meanwhile, the topological edge states were found to be very robust in the presence of strain.

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Chenxiao Zhao, Mengli Hu, Jin Qin, Bing Xia, Canhua Liu, Shiyong Wang, Dandan Guan, Yaoyi Li, Hao Zheng, Junwei Liu, Jinfeng Jia. 2020-09-24. Strain Tunable Semimetal-Topological-Insulator Transition in Monolayer 1T'-WTe2. https://doi.org/10.1103/physrevlett.125.046801

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