Diego Pasquier¹, Oleg V. Yazyev^1*

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), https://doi.org/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.

Materials Cloud sections using this data

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.

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External references

Keywords

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