The research team led by Professors Chen Zhigang and Professor Xu Jingjun at Nankai University has recently made a significant breakthrough in their study of photonic graphene. They have identified a previously unseen boundary in graphene, known as the ‘twig’ boundary. Tor the first time successfully, they have observed this new boundary state and the compact boundary state caused by the topological flat band on the photonic lattice platform, revealing the topological protection of this boundary state and its complementarity with the other three well-known graphene boundaries. This advancement deepens our comprehension of graphene boundary states and topological physics, providing a theoretical underpinning for the application of topological structures in nanoelectronic devices and optical information transmission. The findings, under the title “Photonic Realization of a Generic Type of Graphene Edge States Exhibiting Topological Flat Band,” have been recently published online in the Physical Review Letters.

Professors Chen Zhigang and Professor Song Daohong from Nankai University are the co-corresponding authors of this study.This work was supported by the National Key Research and Development Program of China, the National Natural Science Foundation of China, and the China Postdoctoral Science Foundation.

The paper can be accessed at the following link:

https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.131.013804