2027, Volume 22 Issue 3

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  • RESEARCH ARTICLE
    Yu Zhao, Xin Li, Feilong Yu, Jin Chen, Guanhai Li, Xiaoshuang Chen, Wei Lu

    Square-root topological insulators can inherit edge states from an underlying topological parent system, but existing realizations are typically limited to low degeneracy and small winding numbers. Here, we introduce a general design strategy for extending square-root topological phases to an arbitrary winding number N by combining a fixed structural-subdivision framework with long-range couplings, enabling the number of inherited edge states to increase systematically without raising the root order. We reveal a parity-dependent winding-number phase diagram, where odd and even maximum winding numbers exhibit distinct phase-boundary structures and topological transition sequences. The resulting square-root lattices host N-fold degenerate topological edge states within each of two bulk band gaps, with the corresponding modes exhibiting characteristic fixed-position spatial localization. We also discuss experimentally accessible implementations in photonic waveguide arrays and topolectrical circuits. Our approach provides a scalable route to highly degenerate topological modes and multi-gap wave control in artificial lattices.

Publishing model
2

{"submissionFirstDecision":"30","jcrJfStr":"6.6 (2025)","editorEmail":"wangyy@hep.com.cn"}

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Submission to first decision (median)
30 days

ISSN 2095-0462 (Print)
ISSN 2095-0470 (Online)
CN 11-5994/O4