Regensburg 2019 – wissenschaftliches Programm

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O: Fachverband Oberflächenphysik

O 53: 2D Materials II: Transition Metal Dichalcogenides

O 53.3: Vortrag

Mittwoch, 3. April 2019, 11:00–11:15, H16

Hyperbolic light dispersion in MoTe2 from many-body perturbation theory: impact of dimensionality — •Saeideh Edalati Boostan, Caterina Cocchi, and Claudia Draxl — Physics Department and IRIS Adlershof, Humboldt-Universität zu Berlin, Germany

Among the transition-metal dichalcogenides, MoTe2 shows only a moderate decrease of photolouminescence intensity with increasing number of layers, which makes it an excellent candidate for opto-electronic applications [1]. Therefore, it is essential to gain insight into the response of this material to electro-magnetic radiation with respect to the number of layers. We investigate the electronic and optical properties of MoTe2, considering a monolayer, a bilayer, and its bulk form. Our study is based on many-body perturbation theory including GW and the Bethe-Salpeter equation (BSE), as implemented in the exciting code [2]. Our BSE results reveal that MoTe2 is a natural type-II hyperbolic material in a window of a few eV between the visible and the ultraviolet (UV) region. We emphasize the importance of including many-body effects for a proper quantitative description of this phenomenon. Going from the monolayer to the bulk, the energy window of hyperbolicity is red-shifted by several tenths of an eV. These findings disclose new perspectives for this material in view of applications in plasmonics and nano-imaging.

[1] I. G. Lezama, et al., Nano Lett. 15 (2015) 2336.

[2] A. Gulans, et al., JPCM 26, 36 (2014).