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Title: Directing valley-polarized emission of 3 L WS 2 by photonic crystal with directional circular dichroism
The valley degree of freedom that results from broken inversion symmetry in two-dimensional (2D) transition-metal dichalcogenides (TMDCs) has sparked a lot of interest due to its huge potential in information processing. In this experimental work, to optically address the valley-polarized emission from three-layer (3 L) thick WS2at room temperature, we employ a SiN photonic crystal slab that has two sets of holes in a square lattice that supports directional circular dichroism engendered by delocalized guided mode resonances. By perturbatively breaking the inversion symmetry of the photonic crystal slab, we can simultaneously manipulate s and p components of the radiating field so that these resonances correspond to circularly polarized emission. The emission of excitons from distinct valleys is coupled into different radiative channels and hence separated in the farfield. This directional exciton emission from selective valleys provides a potential route for valley-polarized light emitters, which lays the groundwork for future valleytronic devices.  more » « less
Award ID(s):
2139416
PAR ID:
10531774
Author(s) / Creator(s):
; ; ;
Publisher / Repository:
Optica
Date Published:
Journal Name:
Optics Express
Volume:
32
Issue:
4
ISSN:
1094-4087
Page Range / eLocation ID:
6076
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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