Abstract-Coherent Terahertz Spin-Wave Emission Associated with Ferrimagnetic Domain Wall Dynamics

Se-Hyeok Oh, Se Kwon Kim, Dong-Kyu Lee, Gyungchoon Go, Kab-Jin Kim, Teruo Ono, Yaroslav Tserkovnyak, Kyung-Jin Lee

(Submitted on 2 Jun 2017)

https://arxiv.org/abs/1706.00549

 We theoretically study the dynamics of ferrimagnetic domain walls in the presence of Dzyaloshinskii-Moriya interaction. We find that an application of a DC magnetic field can induce terahertz spin-wave emission by driving ferrimagnetic domain walls, which is not possible for ferromagnetic or antiferromagnetic domain walls. Dzyaloshinskii-Moriya interaction is shown to facilitate the teraherz spin-wave emission in wide ranges of net angular momentum by increasing the Walkerbreakdown field. Moreover, we show that spin-orbit torque combined with Dzyaloshinskii-Moriya interaction also drives a fast ferrimagnetic domain wall motion with emitting terahertz spin-waves in wide ranges of net angular momentum.