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Abstract The rise of quantum science and technologies motivates photonics research to seek new platforms with strong light-matter interactions to facilitate quantum behaviors at moderate light intensities. Topological polaritons (TPs) offer an ideal platform in this context, with unique properties stemming from resilient topological states of light strongly coupled with matter. Here we explore polaritonic metasurfaces based on 2D transition metal dichalcogenides (TMDs) as a promising platform for topological polaritonics. We show that the strong coupling between topological photonic modes of the metasurface and excitons in TMDs yields a topological polaritonic Z2phase. We experimentally confirm the emergence of one-way spin-polarized edge TPs in metasurfaces integrating MoSe2and WSe2. Combined with the valley polarization in TMD monolayers, the proposed system enables an approach to engage the photonic angular momentum and valley and spin of excitons, offering a promising platform for photonic/solid-state interfaces for valleytronics and spintronics.
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This content will become publicly available on November 28, 2025
Valleytronics: Fundamental Challenges and Materials Beyond Transition Metal Chalcogenides
Valleytronics, harnessing the valley degree of freedom in the momentum space, is a potential energy‐efficient approach for information encoding, manipulation, and storage. Valley degree of freedom exists in a few conventional semiconductors, but recently the emerging 2D materials, such as monolayer transition‐metal dichalcogenides (TMDs), are considered more ideal for valleytronics, due to the additional protection from spin‐valley locking enabled by their inversion symmetry breaking and large spin‐orbit coupling. However, current limitations in the valley lifetime, operation temperature, and light‐valley conversion efficiency in existing materials encumber the practical applications of valleytronics. In this article, the valley depolarization mechanisms and recent progress of novel materials are systematically reviewed for valleytronics beyond TMDs. Valley physics is first reviewed and the factors determining the valley lifetime, including the intrinsic electron‐electron and electron‐lattice interactions, as well as extrinsic defect effects. Then, experimentally demonstrated and theoretically proposed valley materials are introduced which potentially improve valley properties through the changes of spin‐orbit coupling, electronic interactions, time‐reversal symmetry, structures, and defects. Finally, the challenges and perspectives are summarized to realize valleytronic devices in the future.
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- Award ID(s):
- 2327827
- PAR ID:
- 10599884
- Publisher / Repository:
- Wiley online library
- Date Published:
- Journal Name:
- Small
- ISSN:
- 1613-6810
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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