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A second wave of topological phenomena in photonics and acoustics

Nature volume 618, pages 687–697 (2023)Cite this article

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Abstract

Light and sound are the most ubiquitous forms of waves, associated with a variety of phenomena and physical effects such as rainbows and echoes. Light and sound, both categorized as classical waves, have lately been brought into unexpected connections with exotic topological phases of matter. We are currently witnessing the onset of a second wave of active research into this topic. The past decade has been marked by fundamental advances comprising two-dimensional quantum Hall insulators and quantum spin and valley Hall insulators, whose topological properties are characterized using linear band topology. Here, going beyond these conventional topological systems, we focus on the latest frontiers, including non-Hermitian, nonlinear and non-Abelian topology as well as topological defects, for which the characterization of the topological features goes beyond the standard band-topology language. In addition to an overview of the current state of the art, we also survey future research directions for valuable applications.

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Fig. 1: Beyond conventional topological systems.
Fig. 2: Non-Hermitian topological phenomena.
Fig. 3: Nonlinearity-induced topological structures.
Fig. 4: Non-Abelian wave physics.
Fig. 5: Topological defects.

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Change history

  • 28 June 2023

    In the version of this article initially published, there was a typo in the text now reading “Interestingly, parallel transport of two degenerate states in the parameter space along an eighth surface of a sphere reproduces the braiding operation,” where the text originally read “a quarter surface.” The text is amended in the HTML and PDF versions of the article.

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Acknowledgements

X.Z. and M.-H.L. are supported by the National Natural Science Foundation of China (grant number 12222407) and the National Key R&D Program of China (grant numbers 2018YFA0306200 and 2021YFB3801800). J.C. acknowledges support from the Spanish Ministry of Science and Innovation through a Consolidación Investigadora grant (CNS2022-135706). J.C. also acknowledges discussions with P. San-Jose.

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Authors and Affiliations

  1. National Laboratory of Solid State Microstructures and College of Engineering and Applied Sciences, Nanjing University, Nanjing, China

    Xiujuan Zhang & Ming-Hui Lu

  2. Hitachi ABB Power Grids Research Center, Baden, Switzerland

    Farzad Zangeneh-Nejad

  3. School of Materials Science and Intelligent Engineering, Nanjing University, Suzhou, China

    Ze-Guo Chen

  4. IMDEA Materials Institute, Madrid, Spain

    Johan Christensen

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Zhang, X., Zangeneh-Nejad, F., Chen, ZG. et al. A second wave of topological phenomena in photonics and acoustics. Nature 618, 687–697 (2023). https://doi.org/10.1038/s41586-023-06163-9

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