Polarization-Controlled Exciton-Polaritons in WS<sub>2</sub> Strongly Coupled with Low-Symmetry Photonic Crystal Nanostructures.

Wang, Yuefeng; Huang, Di; Xia, Meng; Zhou, Jiaxin; Chen, Yuhua; Zhang, Xingwang · Nano Lett · 2024

basic_science · Level V

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Abstract

Atomically thin transition metal dichalcogenides (TMDs) with ambient stable exciton resonances have emerged as an ideal material platform for exciton-polaritons. In particular, the strong coupling between excitons in TMDs and optical resonances in anisotropic photonic nanostructures can form exciton-polaritons with polarization selectivity, which offers a new degree of freedom for the manipulation of the light-matter interaction. In this work, we present the experimental demonstration of polarization-controlled exciton-polaritons in tungsten disulfide (WS<sub>2</sub>) strongly coupled with polarization singularities in the momentum space of low-symmetry photonic crystal (PhC) nanostructures. The utilization of polarization singularities can not only effectively modulate the polarization states of exciton-polaritons in the momentum space but also facilitate or suppress their far field coupling capabilities by tuning the in-plane momentum. Our results provide new strategies for creating polarization-selective exciton-polaritons.