[C-10] Spintronics II

[C-10-03] THz Ferrimagnetic Oscillation Based on the Atomistic Model

〇Xue Zhang¹, Baofang Cai², Jie Ren¹, Zhengping Yuan¹, Yumeng Yang¹, Gengchiau Liang², Zhifeng Zhu¹ (1. Univ.of ShanghaiTech (China), 2. National Univ.of Singapore (Singapore))

Presentation style: Online

https://doi.org/10.7567/SSDM.2022.C-10-03

The magnetization oscillation of ferrimagnets, (FeCo)1-xGdx, driven by the spin transfer torque is studied using the two-dimensional atomistic model. Two oscillation modes are observed, i.e., the exchange mode and the flipped exchange mode, where the former only exists at small Gd composition. The frequency ranges from 300 GHz to 4.3 THz, and it can be controlled in a wide current range from 3×10^11 A/m^2 to 1.9×10^12 A/m^2. The high frequency is mainly occurred in the flipped exchange mode. The frequency increases when the Gd composition is increased. A spatial nonuniform oscillation is also observed when the sample is small. The effect of the Gd composition and the sample size cannot be captured using the macrospin model. Our study helps to understand the THz oscillation generated in ferrimagnets.