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arXiv · 1702.07170

Plasmon modes of bilayer molybdenum disulfide: A density functional study

Zahra Torbatian·Reza Asgari
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Abstract

We explore the collective electronic excitations of bilayer molybdenum disulfide (MoS$_2$) using the density functional theory together with the random phase approximation. The many-body dielectric function and electron energy-loss spectra are calculated using an {\it ab initio} based model involving material-realistic physical properties. The electron energy-loss function of bilayer MoS$_2$ system is found to be sensitive to either electron or hole doping and it is owing to the fact that the Kohn-Sham band dispersions are not symmetric for energies above and below the zero Fermi level. Three plasmon modes are predicted. A damped high-energy mode, one optical mode (in-phase mode) for which the plasmon dispersion exhibits $\sqrt q $ in the long wavelength limit originating from low-energy electron scattering and finally a highly damped acoustic mode (out-of-phase mode).

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Zahra Torbatian, Reza Asgari. 2017-06-06. Plasmon modes of bilayer molybdenum disulfide: A density functional study. https://doi.org/10.1088/1361-648x%2Faa86b9

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