Topological insulators, a fundamental concept in modern condensed matter physics, support localized states at the interfaces between insulators exhibiting different topological phases, which conventionally rely on explicit symmetry breaking. Here, we propose a mechanism to induce a real-space topological phase transition by spontaneous symmetry breaking, thereby constructing an acoustic metagrating to generate nontrivial Jackiw-Rebbi states characterized by robust imaginary band degeneracy. Our experimental implementation verifies the acoustic delocalized interface state with a constant phase jump, demonstrating enhanced high-directivity topological radiation. We foresee that our findings may spark interest in engineering new acoustic topological devices.
@article{arxiv.2504.20076,
title = {Acoustic topological Jackiw-Rebbi states at symmetry broken interfaces},
author = {Yifei Xia and An Chen and Ting Zhang and Jing Yang and Bin Liang and Johan Christensen and Jianchun Cheng},
journal= {arXiv preprint arXiv:2504.20076},
year = {2025}
}