Speaker
Description
Discrete breathers (DBs) are spatially localized vibrational modes ubiquitous in physical systems. Despite decades of research, their mutual interactions represent a fundamental yet unexplored facet of nonlinear dynamics. Here we uncover quantitative interaction laws for DB pairs, encoded in tunable energy beating whose amplitude provides a direct coupling metric shaped by energy mismatch, phase configuration, and a separation yielding exponentially decaying, parity-sensitive coupling. The coupling can be strongly modulated by frequency locking, which emerges only under restricted excitation conditions. A minimal nonlinear dimer encapsulates all salient behaviors across diverse lattice models. These results promote DBs from static energy traps to versatile elements for engineering energy transport, tailoring vibrational spectra, and generating acoustic frequency combs.
Acknowledgements: This work was supported by NSFC under Grant Nos. 12575040, 11905087, 12175090, 11775101, 12247101, and 12465010, by National Key R&D Program of China under Grant No. 2023YFA1407100, by the Fundamental Research Funds for the Central Universities (Grant No. lzujbky-2025-jdzx07), by the Natural Science Foundation of Gansu Province (No. 22JR5RA389, No.25JRRA799), and by the ‘111 Center’ under Grant No. B20063. S. Flach was supported by the Institute for Basic Science through Project Code (No. IBS-R024-D1). W. Fu also acknowledge support by the Youth Talent (Team) Project of Gansu Province (No. 2024QNTD54), the Gansu Province Long-yuan Youth Talent Project, the Fei-tian Scholars Project of Gansu Province, the Leading Talent Project of Tianshui City, and the Innovation Fund from Department of Education of Gansu Province (Grant No. 2023A-106).