The artificial crystals for classical waves provide a good platform to explore the topological physics proposed originally in condensed matter systems. In this paper, acoustic Dirac degeneracy is realized by simply rotating the scatterers in sonic crystals, where the degeneracy is induced accidentally by modulating the scattering strength among the scatterers during the rotation process. This gives a flexible way to create topological phase transition in acoustic systems. Edge states are further observed along the interface separating two topologically distinct gapped sonic crystals.
@article{arxiv.1709.02904,
title = {Acoustic Dirac degeneracy and topological phase transitions realized by rotating scatterers},
author = {Xinhua Wen and Chunyin Qiu and Jiuyang Lu and Hailong He and Manzhu Ke and Zhengyou Liu},
journal= {arXiv preprint arXiv:1709.02904},
year = {2018}
}