Sessions d’accompagnement à l’écriture de projet pour les appels
ERC Consolidator Grant 2017 & Marie S. Curie ITN 2017 + INFODAY Marie S. Curie
➜ 2 jour ERC (campus CNRS) : les 7 et 8 novembre
➜ 2 jours MSCA (GReEn-ER) : les 9 et 10 novembre
+ d’informations : www.fostering-science.com
25 de la rue des martyrs, Grenoble
Exciton states mixing and second harmonics generation in transition metal dichalcogenide monolayers
Optical properties of transition metal dichalcogenides monolayers are governed by the Wannier-Mott excitons forming a series of 1s, 2s, 2p, … hydrogen-like states. The excited excitonic states play important role in the nonlinear optical properties such as two-photon absorption and second harmonics generation. Here we present the theory of the excited excitonic states energy spectrum fine structure. We demonstrate that p- and s-shell excitons are mixed due to the specific D3h point symmetry of the transition metal dichalcogenides monolayers. Hence, both s- and p-shell excitons are simultaneously active in single- and two-photon processes providing an efficient mechanism of the second harmonic generation. The corresponding contribution to the nonlinear susceptibility is calculated.