scholarly journals Terahertz Driven Reversible Topological Phase Transition of Monolayer Transition Metal Dichalcogenides

2021 ◽  
pp. 2003832
Author(s):  
Jian Zhou ◽  
Haowei Xu ◽  
Yongliang Shi ◽  
Ju Li
2D Materials ◽  
2022 ◽  
Author(s):  
Xiangru Kong ◽  
Wei Luo ◽  
Linyang Li ◽  
Mina Yoon ◽  
Tom Berlijn ◽  
...  

Abstract Using ab initio tight-binding approaches, we investigate Floquet band engineering of the 1T’ phase of transition metal dichalcogenides (MX2, M = W, Mo and X = Te, Se, S) monolayers under the irradiation with circularly polarized light. Our first principles calculations demonstrate that light can induce important transitions in the topological phases of this emerging materials family. For example, upon irradiation, Te-based MX2 undergoes a phase transition from quantum spin Hall (QSH) semimetal to time-reversal symmetry broken QSH insulator with a nontrivial band gap of up to 92.5 meV. On the other hand, Se- and S-based MX2 undergoes the topological phase transition from the QSH effect to the quantum anomalous Hall (QAH) effect and into trivial phases with increasing light intensity. From a general perspective, our work brings further insight into non-equilibrium topological systems.


Surfaces ◽  
2020 ◽  
Vol 4 (1) ◽  
pp. 1-8
Author(s):  
Tomasz Kosmala ◽  
Pawel Palczynski ◽  
Matteo Amati ◽  
Luca Gregoratti ◽  
Hikmet Sezen ◽  
...  

Here, we present a proof-of-concept experiment where phase engineering at the nanoscale of 2D transition metal dichalcogenides (TMDC) flakes (from semiconducting 2H phase to metallic 1T phase) can be achieved by thermal annealing of a TMDC/Au/mica system. The local dewetting of Au particles and resulting tensile strain produced on the TMDC flakes, strongly bound to the Au surface through effective S-Au bonds, can induce a local structural phase transition. An important role is also played by the defects induced by the thermal annealing: when vacancies are present, the threshold strain needed to trigger the phase transition is significantly reduced. Scanning photoelectron microscopy (SPEM) was revealed to be the perfect tool to monitor the described phenomena.


Nanoscale ◽  
2018 ◽  
Vol 10 (43) ◽  
pp. 20171-20177 ◽  
Author(s):  
Bingzheng Yan ◽  
Baitao Zhang ◽  
Hongkun Nie ◽  
Guoru Li ◽  
Xiaoli Sun ◽  
...  

1T-titanium selenide (1T-TiSe2), a representative of 1T phase transition metal dichalcogenides (TMDs), exhibits semimetallic behaviour with a nearly zero bandgap structure, which makes it a promising photoelectric material.


2020 ◽  
Vol 8 (13) ◽  
pp. 4432-4440 ◽  
Author(s):  
Xiangyu Zhou ◽  
Haibo Shu ◽  
Qiuqi Li ◽  
Pei Liang ◽  
Dan Cao ◽  
...  

Electron injection leads to the transition of two-dimensional MoX2 (X = S, Se, and Te) nanosheets from the semiconducting H phase to semimetallic T′ phase.


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