High Harmonic Generation in Monolayer and Bilayer of Transition Metal Dichalcogenide

Symmetry

Alexis Chacón¹  Dong-Eon Kim¹  Yeon Lee¹  Dasol Kim¹ 

[1] Department of Physics and Center for Attosecond Science and Technology, POSTECH, Pohang 37673, Korea;

关键词: high-order harmonic generation;    transition metal dichalcogenides;    pseudospin;    Berry curvature;    dipole transition matrix element;    tight-binding model;   

DOI  :  10.3390/sym13122403

来源: DOAJ

【 摘 要 】

In transition metal dichalcogenides (TMDCs), charge carriers have spin, pseudospin, and valley degrees of freedom associated with magnetic moments. The monolayers and bilayers of the TMDCs, in particular, MoS${}_2$, lead to strong couplings between the spin and pseudospin effects. This feature has drawn attention to TMDCs for their potential use in advanced tech devices. Meanwhile, high-order harmonic generation (HHG) has recently been applied to the characterization of the electronic structure of solids, such as energy dispersion, Berry-curvature, and topological properties. Here, we show theoretical results obtained with the ‘philosophy’ of using HHG to investigate the structural effects of the monolayer and bilayers of MoS${}_2$ on nonlinear optical emission. We use a simple model for MoS${}_2$ in the 3R AB staking. We find that the pseudospin and valley indexes (the Berry curvature and the dipole transition matrix element) in TMDC driven by a circularly polarized laser (CPL) can encode in the high-energy photon emissions. This theoretical investigation is expected to pave the way for the ultrafast manipulation of valleytronics and lead to new questions concerning the spin-obit-coupling (SOC) effects on TMDC materials, Weyl Semimetals, and topological phases and transitions in topological insulators.

【 授权许可】

Unknown