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Terahertz topological photonics for on-chip communication


The realization of integrated, low-cost and efficient solutions for high-speed, on-chip communication requires terahertz-frequency waveguides and has great potential for information and communication technologies, including sixth-generation (6G) wireless communication, terahertz integrated circuits, and interconnects for intrachip and interchip communication. However, conventional approaches to terahertz waveguiding suffer from sensitivity to defects and sharp bends. Here, building on the topological phase of light, we experimentally demonstrate robust terahertz topological valley transport through several sharp bends on the all-silicon chip. The valley kink states are excellent information carriers owing to their robustness, single-mode propagation and linear dispersion. By leveraging such states, we demonstrate error-free communication through a highly twisted domain wall at an unprecedented data transfer rate (exceeding ten gigabits per second) that enables real-time transmission of uncompressed 4K high-definition video (that is, with a horizontal display resolution of approximately 4,000 pixels). Terahertz communication with topological devices opens a route towards terabit-per-second datalinks that could enable artificial intelligence and cloud-based technologies, including autonomous driving, healthcare, precision manufacturing and holographic communication.

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Fig. 1: On-chip THz VPC and its bulk band diagram.
Fig. 2: Phase diagram and topological valley kink states at the domain wall.
Fig. 3: Experimental observation of robust topological valley kink states along a twisted domain wall in a large-scale THz photonic chip.
Fig. 4: Terahertz communication based on robust topological valley transport.

Data availability

The data that support the plots within this paper and other findings of this study are available from the corresponding author upon reasonable request.


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We thank Z. Xu at Zhejiang University for discussions, and J. Kim and Y. Nishida at Rohm Co. Ltd. for their help with experiments. Y. Yang, P.P., B.Z. and R.S. acknowledge research funding support from the Singapore Ministry of Education (grant numbers MOE2017-T2-1-110, MOE2018-T2-1-022(S) and MOE2016-T3-1-006(S)) and the National Research Foundation (NRF), Singapore and Agence Nationale de la Recherche (ANR), France (grant number NRF2016-NRF-ANR004). Work at Osaka University is supported in part by the Core Research for Evolutional Science and Technology (CREST) programme of the Japan Science and Technology Agency (grant number JPMJCR1534), KAKENHI, Japan (grant number 17H01764).

Author information




Y. Yang created the design, performed theoretical analysis and simulations, and helped to write the manuscript. Y. Yamagami performed simulations, experiments and data analysis. X.Y. helped with the design and performed the experiments. P.P. helped with the experiment design and simulations. J.W. helped with the communication experiment and data analysis. B.Z. provided input on topological protection. M.F. planned and co-led the project, performed the data analysis, and helped to write the manuscript. T.N. guided the project and communication experiments. R.S. planned and led the project and helped to write the manuscript. All authors contributed to the manuscript.

Corresponding authors

Correspondence to Masayuki Fujita or Ranjan Singh.

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The authors declare no competing interests.

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Supplementary information

Supplementary Information

Supplementary Figs. 1–13, refs. 1–20 and Table 1.

Supplementary Video 1

Video data transmission through topological waveguide.

Supplementary Video 2

Wireless data transmission through topological device.

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Yang, Y., Yamagami, Y., Yu, X. et al. Terahertz topological photonics for on-chip communication. Nat. Photonics 14, 446–451 (2020).

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