materialscloud:2020.0042/v1

Unified picture of lattice instabilities in metallic transition metal dichalcogenides

Diego Pasquier1, Oleg V. Yazyev1*

1 Institute of Physics, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland

* Corresponding authors emails: oleg.yazyev@epfl.ch
DOI10.24435/materialscloud:2020.0042/v1 [version v1]

Publication date: Apr 28, 2020

How to cite this record

Diego Pasquier, Oleg V. Yazyev, Unified picture of lattice instabilities in metallic transition metal dichalcogenides, Materials Cloud Archive 2020.0042/v1 (2020), doi: 10.24435/materialscloud:2020.0042/v1.

Description

Transition metal dichalcogenides (TMDs) in the 1T polymorph are subject to a rich variety of periodic lattice distortions, often referred to as charge-density waves (CDWs) when not too strong. We study from first principles the fermiology and phonon dispersion of three representative single-layer transition metal disulfides with different occupation of the t2g subshell: TaS2 (t1 2g), WS2 (t2 2g), and ReS2 (t3 2g) across a broad range of doping levels. While strong electron-phonon interactions are at the heart of these instabilities, we argue that away from half-filling of the t2g subshell, the doping dependence of the calculated CDW wave vector can be explained from simple fermiology arguments, so that a weak-coupling nesting picture is a useful starting point for understanding. On the other hand, when the t2g subshell is closer to half-filling, we show that nesting is irrelevant, while a real-space strong-coupling picture of bonding Wannier functions is more appropriate and simple bond-counting arguments apply. Our study thus provides a unifying picture of lattice distortions in 1T TMDs that bridges the two regimes, while the crossover between these regimes can be attained by tuning the filling of the t2g orbitals.

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Files

File name Size Description
PhysRevB100_201103_data.zip
MD5md5:c0a212d145ddbd59725d5d25baa0bff7
19.2 MiB The archive the input and output files of the calculations band structures, susceptibility, phonon dispersions and Wannierization.
README.txt
MD5md5:0c4ffa46a83789c627bac33cd84c98b3
225 Bytes Brief description of the archive contents.

License

Files and data are licensed under the terms of the following license: Creative Commons Attribution 4.0 International.

External references

Journal reference
D. Pasquier and O. V. Yazyev, Phys. Rev. B 100, 201103(R) (2019) doi:10.1103/PhysRevB.100.201103
Preprint

Keywords

transition metal dichalcogenides charge density wave lattice distortion Fermi surface nesting phonons susceptibility chemical bonding Wannier functions EPFL

Version history:

2020.0042/v1 (version v1) [This version] Apr 28, 2020 DOI10.24435/materialscloud:2020.0042/v1