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arXiv · 2103.04043

Third-order topological insulator in three-dimensional lattice of magnetic vortices

Z. -X. Li·Zhenyu Wang·Zhizhi Zhang·Yunshan Cao·Peng Yan
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Abstract

Recent acoustic and electrical-circuit experiments have reported the third-order (or octupole) topological insulating phase, while its counterpart in classical magnetic systems is yet to be realized. Here we explore the collective dynamics of magnetic vortices in three-dimensional breathing cuboids, and find that the vortex lattice can support zero-dimensional corner states, one-dimensional hinge states, two-dimensional surface states, and three-dimensional bulk states, when the ratio of alternating intralayer and interlayer bond lengths goes beyond a critical value. We show that only the corner states are stable against external frustrations because of the topological protection. Full micromagnetic simulations verify our theoretical predictions with good agreement.

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Z. -X. Li, Zhenyu Wang, Zhizhi Zhang, Yunshan Cao, Peng Yan. 2021-03-06. Third-order topological insulator in three-dimensional lattice of magnetic vortices. https://doi.org/10.1103/physrevb.103.214442

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