Imperial College London
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ProfessorJohannesLischner

Faculty of Engineering, Department of Materials

Professor of Theory and Simulation of Materials
 
 
 
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Contact

 

+44 (0)20 7594 9949j.lischner

 
 
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Location

 

342Bessemer BuildingSouth Kensington Campus

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Summary

 

Publications

Citation

BibTex format

@article{Vitale:2021:2053-1583/ac15d9,
author = {Vitale, V and Atalar, K and Mostofi, AA and Lischner, J},
doi = {2053-1583/ac15d9},
journal = {2D Materials},
title = {Flat band properties of twisted transition metal dichalcogenide homo- andheterobilayers of MoS2, MoSe2, WS2 and WSe2},
url = {http://dx.doi.org/10.1088/2053-1583/ac15d9},
volume = {8},
year = {2021}
}
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RIS format (EndNote, RefMan)

TY  - JOUR
AB  - Twisted bilayers of two-dimensional materials, such as twisted bilayergraphene, often feature flat electronic bands that enable the observation ofelectron correlation effects. In this work, we study the electronic structureof twisted transition metal dichalcogenide (TMD) homo- and heterobilayers thatare obtained by combining MoS$_2$, WS$_2$, MoSe$_2$ and WSe$_2$ monolayers, andshow how flat band properties depend on the chemical composition of the bilayeras well as its twist angle. We determine the relaxed atomic structure of thetwisted bilayers using classical force fields and calculate the electronic bandstructure using a tight-binding model parametrized from first-principlesdensity-functional theory. We find that the highest valence bands in thesesystems can derive either from $\Gamma$-point or $K$/$K'$-point states of theconstituent monolayers. For homobilayers, the two highest valence bands arecomposed of monolayer $\Gamma$-point states, exhibit a graphene-like dispersionand become flat as the twist angle is reduced. The situation is morecomplicated for heterobilayers where the ordering of $\Gamma$-derived and$K$/$K'$-derived states depends both on the material composition and also thetwist angle. In all systems, qualitatively different band structures areobtained when atomic relaxations are neglected.
AU  - Vitale,V
AU  - Atalar,K
AU  - Mostofi,AA
AU  - Lischner,J
DO  - 2053-1583/ac15d9
PY  - 2021///
SN  - 2053-1583
TI  - Flat band properties of twisted transition metal dichalcogenide homo- andheterobilayers of MoS2, MoSe2, WS2 and WSe2
T2  - 2D Materials
UR  - http://dx.doi.org/10.1088/2053-1583/ac15d9
UR  - http://arxiv.org/abs/2102.03259v2
UR  - http://hdl.handle.net/10044/1/90887
VL  - 8
ER  -
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