Topological phase transitions of non-Hermitian periodic and disordered elastic systems
- verfasst von
- Runcheng Cai, Yabin Jin, Yan Pennec, Timon Rabczuk, Xiaoying Zhuang, Bahram Djafari-Rouhani
- Abstract
Topological states have been extensively explored across diverse wave systems in recent decades. However, most research has focused on the periodic and Hermitian systems, while the roles of non-Hermiticity and disorder in topological properties need to be further explored, especially for two-dimensional systems. In this paper, the topological phase transitions induced by periodic and disordered on-site non-Hermitian modulations in one-dimensional (1D) and two-dimensional (2D) elastic systems and their topological edge and corner states are systemically studied. First, an analytical approach based on a generalization of the 1D Su–Schrieffer–Heeger (SSH) model is applied to investigate the full topological phase evolutions with different physical parameters and non-Hermitian strengths. It is found that an initially trivial system can become nontrivial under periodic or moderately disordered non-Hermitian modulations while increasing the level of randomness induces a nontrivial to trivial phase transition. Then, an elastic analog of the 1D SSH model constructed by elastic square plates with thin connecting beams is proposed, where the non-Hermitian modulations are introduced by piezoelectric patches with a feedback control loop. The evolutions of topological phases and their corresponding topological edge modes are numerically demonstrated in this elastic platform. Furthermore, the analytical SSH model and the realistic elastic platform are extended to 2D structures and their topological properties are deeply investigated. Studies indicate that periodic non-Hermitian modulations can drive trivial-nontrivial transitions and topological edge and higher-order corner states would appear for 2D structures. However, the 2D structures are more sensitive to the disorder and trivial-nontrivial phase transitions only survive under the small disorder. Larger non-Hermitian strength would result in the emergence of more nontrivial bandgaps and topological edge states. The main novelties of the paper are the proposition of a new elastic platform with feedback control for the study of non-Hermitian topological systems, a comprehensive analysis of combined effects of non-Hermiticity and disorders on topological properties, and the extension of 1D to 2D structures. Our work offers a reliable platform for studying topological properties in 1D and 2D non-Hermitian systems and designing active wave control devices.
- Organisationseinheit(en)
-
Institut für Photonik
- Externe Organisation(en)
-
Tongji University
Université de Lille 1
East China University of Science and Technology
Bauhaus-Universität Weimar
- Typ
- Artikel
- Journal
- International Journal of Mechanical Sciences
- Band
- 294
- Anzahl der Seiten
- 14
- ISSN
- 0020-7403
- Publikationsdatum
- 15.05.2025
- Publikationsstatus
- Veröffentlicht
- Peer-reviewed
- Ja
- ASJC Scopus Sachgebiete
- Tief- und Ingenieurbau, Allgemeine Materialwissenschaften, Physik der kondensierten Materie, Luft- und Raumfahrttechnik, Meerestechnik, Werkstoffmechanik, Maschinenbau, Angewandte Mathematik
- Elektronische Version(en)
-
https://doi.org/10.1016/j.ijmecsci.2025.110241 (Zugang:
Geschlossen)
