Tunable Magnonic Chern Bands and Chiral Spin Currents in Magnetic Multilayers

Zhongqiang Hu | Liang Fu | Luqiao Liu

Realization of novel topological phases in magnonic band structures represents a new opportunity for the development of spintronics and magnonics with low power consumption. In this work, we show that in antiparallelly aligned magnetic multilayers, the long-range, chiral dipolar interaction
generates bulk bands with non-zero Chern integers and magnonic surface states carrying chiral spin currents. The surface states are strictly localized without decay into the bulk, and can be easily toggled between non-trivial and trivial phases through an external magnetic field. The realization
of chiral surface spin currents represents a magnonic implementation of the coupled wire model that has been extensively explored in electronic systems. Our work presents an easy-to-implement system for realizing topological magnonic surface states and low-dissipation spin current transport
in a tunable manner.

Funding Sources: AFOSR under award FA9550-19-1-0048 | National Science Foundation under award DMR-2104912