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Title: Naturally occurring van der Waals heterostructure lengenbachite with strong in-plane structural and optical anisotropy
Abstract

Lengenbachite is a naturally occurring layered mineral formed with alternating stacks of two constituent PbS-like and M2S3-like two-dimensional (2D) material layers due to the phase segregation process during the formation. Here, we demonstrate to achieve van der Waals (vdW) heterostructures of lengenbachite down to a few layer-pair thickness by mechanical exfoliation of bulk lengenbachite mineral. The incommensurability between the constituent isotropic 2D material layers makes the formed vdW heterostructure exhibit strong in-plane structural anisotropy, which leads to highly anisotropic optical responses in lengenbachite thin flakes, including anisotropic Raman scattering, linear dichroism, and anisotropic third-harmonic generation. Moreover, we exploit the nonlinear optical anisotropy for polarization-dependent intensity modulation of the converted third-harmonic optical vortices. Our study establishes lengenbachite as a new natural vdW heterostructure-based 2D material with unique optical properties for realizing anisotropic optical devices for photonic integrated circuits and optical information processing.

Authors:
; ;
Award ID(s):
2204163 1552871
Publication Date:
NSF-PAR ID:
10360588
Journal Name:
npj 2D Materials and Applications
Volume:
5
Issue:
1
ISSN:
2397-7132
Publisher:
Nature Publishing Group
Sponsoring Org:
National Science Foundation
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