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arXiv · 2102.06325

Tunable plasmon-enhanced second-order optical nonlinearity in transition metal dichalcogenide nanotriangles

F. Karimi·S. Soleimanikahnoj·I. Knezevic
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Abstract

The development of nanomaterials with a large nonlinear susceptibility is essential for nonlinear nanophotonics. We show that transition-metal-dichalcogenide (TMD) nanotriangles have a large effective second-order susceptibility [$\chi^{(2)}$] at mid-infrared to near-infrared frequencies owing to their broken centrosymmetry. $\chi^{(2)}$ is calculated within the density-matrix formalism that accounts for dissipation and screening. $\chi^{(2)}$ peaks in the vicinity of both two-photon resonances (specified by the geometry) and plasmon resonances (tunable via the carrier density). Aligning the resonances yields the values of $\chi^{(2)}$ as high as $10^{-6}$ m/V. These findings underscore the potential of TMD nanotriangles for nonlinear nanophotonics, particularly second-harmonic generation.

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F. Karimi, S. Soleimanikahnoj, I. Knezevic. 2021-02-12. Tunable plasmon-enhanced second-order optical nonlinearity in transition metal dichalcogenide nanotriangles. https://doi.org/10.1103/physrevb.103.l161401

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