DATE2024.04.12 #Press Releases
Elucidating the Fundamental Principles of Nonlinear Topological Materials
Disclaimer: machine translated by DeepL which may contain errors.
--Toward Design Principles for Robust and Flexible Devices--
Graduate School of Engineering, The University of Tokyo
School of Science, The University of Tokyo
Japan Science and Technology Agency
Abstract of Presentation
A research group led by Graduate Student Kazuki Sone, Lecturer Masahiko Ezawa, Assistant Professor Nobuyuki Yoshioka, Professor Takahiro Sagawa, and Associate Professor Yuto Ashida of Department of Physics, Graduate School of Engineering, The University of Tokyo, has introduced a new topological index in a two-dimensional nonlinear material and demonstrated that it corresponds to an edge state localized at the edge of the sample. The group has theoretically shown that the bulk-edge correspondence holds, in which a new topological index is introduced in a two-dimensional nonlinear material and it corresponds to the edge state localized at the edge of the sample. Furthermore, as a phenomenon unique to nonlinear systems, we revealed the existence of a phase transition in which the topological phase changes depending on the strength of the nonlinearity, and showed that it can be predicted by the topological exponent introduced in this study. While most previous studies of topological materials have been limited to linear systems, this study is a major step forward in extending them to nonlinear systems. Furthermore, it is expected to lead to the development of devices that combine the robustness against noise due to the effect of topology and the flexibility due to the effect of nonlinearity.
The research results were published in Nature Physics on April 11, 2024.
Figure: Topological phase transition induced by nonlinearity. The topological change is realized by nonlinear effects caused by the gathering of a large number of yellow particles, the medium of the wave.
For more information, please visit the website of the Graduate School of Engineering, The University of Tokyo.（in Japanese）
Journals
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Journal name Title of paper Nonlinearity-induced topological phase transition characterized by the nonlinear Chern number