Journal Article

FZJ-2017-04490

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png MoTe2 is a good match for GeI by preserving quantum spin Hall phase

Li, X. ; Dai, Y. (Corresponding author) ; Niu, C.FZJ* ; Ma, Y. ; Wei, W. ; Huang, B.

2017
Tsinghua Press [S.l.]

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Please use a persistent id in citations: doi:10.1007/s12274-017-1488-4

Abstract: Quantum spin Hall (QSH) insulator is a new class of materials that is quickly becoming mainstream in condensed-matter physics. The main obstacle for the development of QSH insulators is that their strong interactions with substrates make them difficult to study experimentally. In this study, using density functional theory, we discovered that MoTe2 is a good match for a GeI monolayer. The thermal stability of a van der Waals GeI/MoTe2 heterosheet was examined via molecular-dynamics simulations. Simulated scanning tunneling microscopy revealed that the GeI monolayer perfectly preserves the bulked honeycomb structure of MoTe2. The GeI on MoTe2 was confirmed to maintain its topological band structure with a sizable indirect bulk bandgap of 0.24 eV by directly calculating the spin Chern number to be −1. As expected, the electron mobility of the GeI is enhanced by MoTe2 substrate restriction. According to deformation-potential theory with the effective-mass approximation, the electron mobility of GeI/MoTe2 was estimated as 372.7 cm2·s−1·V−1 at 300 K, which is 20 times higher than that of freestanding GeI. Our research shows that traditional substrates always destroy the topological states and hinder the electron transport in QSH insulators, and pave way for the further realization and utilization of QSH insulators at room temperature.

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Contributing Institute(s):

1. Quanten-Theorie der Materialien (IAS-1)
2. Quanten-Theorie der Materialien (PGI-1)
3. JARA-FIT (JARA-FIT)
4. JARA - HPC (JARA-HPC)

Research Program(s):

1. 142 - Controlling Spin-Based Phenomena (POF3-142) (POF3-142)

Appears in the scientific report 2017

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Database coverage:
; Current Contents - Engineering, Computing and Technology ; Current Contents - Physical, Chemical and Earth Sciences ; IF >= 5 ; JCR ; SCOPUS ; Science Citation Index Expanded ; Thomson Reuters Master Journal List ; Web of Science Core Collection

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