Linear and nonlinear optical response based on many-body GW-Bethe-Salpeter and Kadanoff-Baym approaches for two-dimensional layered semiconductors

Fuente: arXiv
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Autores principales: Skachkov, Dmitry, Englund, Dirk R., Leuenberger, Michael N.
Formato: Preprint
Publicado: 2024
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author Skachkov, Dmitry
Englund, Dirk R.
Leuenberger, Michael N.
author_facet Skachkov, Dmitry
Englund, Dirk R.
Leuenberger, Michael N.
contents The family of 2D layered semiconductors, including transition metal chalcogenides (TMCs) of the form MX (M=Ga, In; X=S, Se, Te) exhibit exceptional nonlinear optical properties. The energetically most favorable crystal ordering for nonlinear response is the AB layer stacking, which breaks central inversion symmetry for an arbitrary number of layers, resulting in non-zero off-diagonal elements of the $χ^{(2n')}$ tensor, $n'$ being a positive integer, for arbitrary thickness of the materials. We perform first-principles many-body calculations of bandstructures and linear and nonlinear optical responses of monolayer (ML) and bulk TMC crystals based on $GW$-Bethe-Salpeter and Kadanoff-Baym approaches in and out of equilibrium, respectively, while taking many-body band gap renormalization and excitonic effects into account. We develop a detailed analysis of the linear and nonlinear optical selection rules by means of group and representation theory. We observe the general trend that the lowest-energy excitons are dark in 2D ML TMCs whereas they are bright or mixed bright-dark in 3D bulk TMCs, which we attribute to the difference between spatially dependent screening in 2D and constant screening in 3D. In particular, we derive general formulas for the nonlinear optical response based on exciton states in semiconductor materials. We find anti-bound excitons in ML GaS, which we attribute to dominant exciton exchange interaction. We show that by choosing elements with larger mass and by reducing the detuning energy it is possible to increase the nonlinear response not only for $χ^{(2)}$ and $χ^{(3)}$, responsible for SHG and third harmonic generation (THG), but also in general for $χ^{(n)}$ nonlinear response with $n>3$, giving rise to high harmonic generation (HHG) in 2D semiconductor materials.
format Preprint
id arxiv_https___arxiv_org_abs_2410_06218
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Linear and nonlinear optical response based on many-body GW-Bethe-Salpeter and Kadanoff-Baym approaches for two-dimensional layered semiconductors
Skachkov, Dmitry
Englund, Dirk R.
Leuenberger, Michael N.
Materials Science
Mesoscale and Nanoscale Physics
The family of 2D layered semiconductors, including transition metal chalcogenides (TMCs) of the form MX (M=Ga, In; X=S, Se, Te) exhibit exceptional nonlinear optical properties. The energetically most favorable crystal ordering for nonlinear response is the AB layer stacking, which breaks central inversion symmetry for an arbitrary number of layers, resulting in non-zero off-diagonal elements of the $χ^{(2n')}$ tensor, $n'$ being a positive integer, for arbitrary thickness of the materials. We perform first-principles many-body calculations of bandstructures and linear and nonlinear optical responses of monolayer (ML) and bulk TMC crystals based on $GW$-Bethe-Salpeter and Kadanoff-Baym approaches in and out of equilibrium, respectively, while taking many-body band gap renormalization and excitonic effects into account. We develop a detailed analysis of the linear and nonlinear optical selection rules by means of group and representation theory. We observe the general trend that the lowest-energy excitons are dark in 2D ML TMCs whereas they are bright or mixed bright-dark in 3D bulk TMCs, which we attribute to the difference between spatially dependent screening in 2D and constant screening in 3D. In particular, we derive general formulas for the nonlinear optical response based on exciton states in semiconductor materials. We find anti-bound excitons in ML GaS, which we attribute to dominant exciton exchange interaction. We show that by choosing elements with larger mass and by reducing the detuning energy it is possible to increase the nonlinear response not only for $χ^{(2)}$ and $χ^{(3)}$, responsible for SHG and third harmonic generation (THG), but also in general for $χ^{(n)}$ nonlinear response with $n>3$, giving rise to high harmonic generation (HHG) in 2D semiconductor materials.
title Linear and nonlinear optical response based on many-body GW-Bethe-Salpeter and Kadanoff-Baym approaches for two-dimensional layered semiconductors
topic Materials Science
Mesoscale and Nanoscale Physics
url https://arxiv.org/abs/2410.06218