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arXiv · 1601.01707

Valley Plasmonics in the Dichalcogenides

R. E. Groenewald·M. Rösner·G. Schönhoff·S. Haas·T. O. Wehling
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Abstract

The rich phenomenology of plasmonic excitations in the dichalcogenides is analyzed as a function of doping. The many-body polarization, the dielectric response function and electron energy loss spectra are calculated using an ab initio based model involving material-realistic Coulomb interactions, band structure and spin-orbit coupling. Focusing on the representative case of MoS$_2$, a plethora of plasmon bands are observed, originating from scattering processes within and between the conduction or valence band valleys. We discuss the resulting square-root and linear collective modes, arising from long-range versus short-range screening of the Coulomb potential. We show that the multi-orbital nature of the bands and spin-orbit coupling strongly affects inter-valley scattering processes by gapping certain two-particle modes at large momentum transfer.

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R. E. Groenewald, M. Rösner, G. Schönhoff, S. Haas, T. O. Wehling. 2016-01-07. Valley Plasmonics in the Dichalcogenides. https://doi.org/10.1103/physrevb.93.205145

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