2018/04/08 by Yuhao Kang, Xiaojun Cheng, Xiang Ni +2 · 1 citation
Physics and Astronomy · #physics.app-ph #cond-mat.mes-hall #physics.optics
paper · pdf · doi:10.1038/s41467-018-05408-w
published as Nat. Commun. 9, 3029 (2018)
arxiv created 2018/04/08 · arxiv updated 2018/12/18
Pseudo-spin and valley degrees of freedom (DOFs) engineered in photonic analogues of topological insulators (TI) 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 TIs carrying different spin-valley Chern numbers. These results open up the possibility of using the valley DOF to control the flow of optical signals in 2D structures.