Recently, a research team led by Associate Professor Ruo-Yang Zhang, Professor Yun Lai from the School of Physics at Nanjing University, in collaboration with Professor Xiaohan Cui from Southeast University and Professor Che Ting Chan from the Hong Kong University of Science and Technology, has made new progress in ultracompact topological photonic waveguides. The team proposed and experimentally demonstrated, for the first time, an integrated topological photonic waveguide architecture that requires no topological insulator cladding. This work overturns the conventional design paradigm in which topological photonic waveguides must rely on bulky topological insulators, achieving multi-lane unidirectional light guiding with both 100% spatial utilization efficiency and topological protection. By breaking the long-held assumption that topological transport must rely on interface states, this discovery opens new possibilities for high-density, crosstalk-free on-chip photonic integrated circuits and optical computing chips. This work was published in the journal Nature, entitled "Insulator-free topological photonic multi-lane highways."

Fig. 1: Mechanism of insulator-free topological photonic multi-lane highways.

Publication link: https://www.nature.com/articles/s41586-026-10817-9