Role of Interlayer Coupling in the Second Harmonic Generation of Bilayer Transition-metal Dichalcogenides

Abstract

Little is known about the role of weak interlayer coupling in the second harmonic generation (SHG) effects of two-dimensional van der Waals (vdW) systems. In this article, taking homo-bilayer $Mo{S}_2/Mo{S}_2$ and hetero-bilayer $Mo{S}_2/MoS{e}_2$ as typical examples, we have systemically investigated their SHG susceptibilities as a function of interlayer hopping strength using first-principles calculations. For the SHG at zero frequency limit of both $Mo{S}_2/Mo{S}_2$ and $Mo{S}_2/MoS{e}_2$, although the increase of tint can increase the intensities of interlayer optical transitions (IOT), the increased band repulsion around G point can eventually decrease their SHG values; the larger the tint, the smaller the SHG response. For the SHG spectra of $Mo{S}_2/MoS{e}_2$ in the low photon-energy region, opposite to the $Mo{S}_2/Mo{S}_2$, their peak values are very sensitive to the variable tint, due to the strong $t_{int}$-dependent IOT dominating in the band edge; the larger the tint, the larger the SHG. For the SHG of $Mo{S}_2/Mo{S}_2$ in the high photon-energy region, comparing to the $Mo{S}_2/MoS{e}_2$, their peak values will decrease in a much more noticeable way as the $t_{int}$ increases, due to the larger reduction of band nesting effect. Our study not only can successfully explain the puzzling experimental observations for the different SHG responses in different bilayer transition-metal dichalcogenides under variable tint, but also may provide a general understanding for designing controllable the SHG effects in the vdW systems.

References in corpus (25)

• Atomically thin MoS2: A new direct-gap semiconductor
• Magic-angle graphene superlattices: a new platform for unconventional superconductivity
• 2D materials and van der Waals heterostructures
• Maximally localized Wannier functions: Theory and applications
• Ultrafast Charge Transfer in Atomically Thin MoS2/WS2 Heterostructures
• Optical signature of symmetry variations and spin-valley coupling in atomically thin tungsten dichalcogenides
• Probing Excitonic Dark States in Single-layer Tungsten Disulfide
• Three-band tight-binding model for monolayers of group-VIB transition metal dichalcogenides
• Observation of Intense Second Harmonic Generation from MoS${}_2$ Atomic Crystals
• Electrical Control of Second-Harmonic Generation in a WSe2 Monolayer Transistor
• Giant and nonreciprocal second harmonic generation from layered antiferromagnetism in bilayer CrI3
• Photocarrier relaxation in two-dimensional semiconductors
• Magnetoelectric effects and valley controlled spin quantum gates in transition metal dichalcogenide bilayers
• \textit{Ab-initio} Tight-Binding Hamiltonian for Transition Metal Dichalcogenides
• Evidence of an odd-parity hidden order in a spin-orbit coupled correlated iridate
• A Tunable Phonon-Exciton Fano System in Bilayer Graphene
• Nonlinear twistoptics at symmetry-broken interfaces
• Strain-tunable van der Waals interactions in few-layer black phosphorus
• Theory of second harmonic generation in few-layered MoS2
• Quantitative relationship between polarization differences and the zone-averaged shift photocurrent
• Exciton states in monolayer MoSe2: impact on interband transitions
• Defect healing and charge transfer mediated valley polarization in MoS${}_2$/MoSe${}_2$/MoS${}_2$ trilayer van der Waals heterostructures
• Anomalous Dirac Plasmons in 1D Topological Electrides
• Deep-ultraviolet Layered Oxide B2S2O9 with Strong and Robust Second Harmonic Generation
• Density-independent plasmons for terahertz-stable topological metamaterials

Cited by in corpus (4)

• Giant Bulk Electro-photovoltaic Effect in Hetero-nodal-line Systems
• Giant and controllable nonlinear magneto-optical effects in two-dimensional magnets
• Engineering Interlayer Hybridization in Energy Space via Dipolar Overlayers
• Effects of Reduced Interlayer Interactions on the K-point Excitons of MoS${}_2$ Nanoscrolls