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Pseudo-spin-valley coupled edge states in a photonic topological insulator.

ABSTRACT: Pseudo-spin and valley degrees of freedom engineered in photonic analogues of topological insulators provide potential approaches to optical encoding and robust signal transport. Here we observe a ballistic edge state whose spin-valley indices are locked to the direction of propagation along the interface between a valley photonic crystal and a metacrystal emulating the quantum spin-Hall effect. We demonstrate the inhibition of inter-valley scattering at a Y-junction formed at the interfaces between photonic topological insulators carrying different spin-valley Chern numbers. These results open up the possibility of using the valley degree of freedom to control the flow of optical signals in 2D structures.

SUBMITTER: Kang Y

PROVIDER: S-EPMC6072787 | biostudies-literature | 2018 Aug

REPOSITORIES: biostudies-literature

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Pseudo-spin-valley coupled edge states in a photonic topological insulator.

Kang Yuhao Y Ni Xiang X Cheng Xiaojun X Khanikaev Alexander B AB Genack Azriel Z AZ

Nature communications 20180802 1

Pseudo-spin and valley degrees of freedom engineered in photonic analogues of topological insulators provide potential approaches to optical encoding and robust signal transport. Here we observe a ballistic edge state whose spin-valley indices are locked to the direction of propagation along the interface between a valley photonic crystal and a metacrystal emulating the quantum spin-Hall effect. We demonstrate the inhibition of inter-valley scattering at a Y-junction formed at the interfaces bet ...[more]

PMID: 30072759

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