Department of Physics, Queens College of the City University of New York, Queens, New York 11367, USA.
The Graduate Center of the City University of New York, New York, New York 10016, USA.
Nat Mater. 2016 May;15(5):542-8. doi: 10.1038/nmat4573. Epub 2016 Feb 22.
The discovery of topological photonic states has revolutionized our understanding of electromagnetic propagation and scattering. Endowed with topological robustness, photonic edge modes are not reflected from structural imperfections and disordered regions. Here we demonstrate robust propagation along reconfigurable pathways defined by synthetic gauge fields within a topological photonic metacrystal. The flow of microwave radiation in helical edge modes following arbitrary contours of the synthetic gauge field between bianisotropic metacrystal domains is unimpeded. This is demonstrated in measurements of the spectrum of transmission and time delay along the topological domain walls. These results provide a framework for freely steering electromagnetic radiation within photonic structures.
拓扑光子态的发现彻底改变了我们对电磁波传播和散射的理解。光子边缘模式具有拓扑鲁棒性，不会被结构缺陷和无序区域反射。在这里，我们展示了在拓扑光子超晶格内通过合成规范场定义的可重构路径中的稳健传播。微波辐射在双各向异性超晶格域之间的任意合成规范场轮廓的螺旋边缘模式中流畅地传播，这在拓扑畴壁上传输谱和时间延迟的测量中得到了证明。这些结果为在光子结构中自由引导电磁波提供了框架。
