We propose a realization of higher-order topological phases in a spring-mass model with a breathing kagome structure. To demonstrate the existence of the higher-order topological phases, we characterize the topological properties and show that the corner states appear under the fixed boundary condition. To characterize the topological properties, we introduce a formula for the Z3 Berry phases in the Brillouin zone. From the numerical result of this Z3 Berry phase, we have elucidated that coupling between the longitudinal and transverse modes yields a state characterized by the Berry phase 32π for our mechanical breathing kagome model. In addition, we suggest that the corner states can be detected experimentally through a forced vibration.
@article{arxiv.1909.02828,
title = {Higher-order topological phases in a spring-mass model on a breathing kagome lattice},
author = {Hiromasa Wakao and Tsuneya Yoshida and Hiromu Araki and Tomonari Mizoguchi and Yasuhiro Hatsugai},
journal= {arXiv preprint arXiv:1909.02828},
year = {2020}
}