| Autor: |
Ingi Kim, Zhaoyin Sun, Satoshi Iwamoto, Yasuhiko Arakawa |
| Rok vydání: |
2019 |
| Předmět: |
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| Zdroj: |
2019 Compound Semiconductor Week (CSW). |
| DOI: |
10.1109/iciprm.2019.8819361 |
| Popis: |
Multi-band valley-protected topological edge states is numerically demonstrated in GaAs-based phononic crystal (PnC) slabs. Two Dirac degeneracies at different frequencies are lifted by rotation of triangular holes in the unit cells breaking the mirror symmetry, and complete phononic bandgaps (PnBGs) are obtained near each frequency. The topological properties of both PnBGs depend on the rotating direction of the triangular holes, which allows the structures to have different valley vortex chirality. The vortex patterns of the valley states near PnBGs show the opposite rotating direction of the mechanical energy flux in different PnC slabs, which indicate different topological properties. At the boundary between the topologically different structures, the valley-protected edge states appear in each bandgap via the bulk-edge correspondence. The robust transports of the both valley-protected edge states are clearly observed in Z-shaped wave guides with the sharp corners of the boundary by numerical simulation. Our design paves the way toward multi-functional topological phononic devices with low energy loss through the multiple complete PnBGs. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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