Year: 2022
Type: article
Abstract: Ferrimagnets (FIMs) can function as high-frequency antiferromagnets while being easy to detect as ferromagnets, offering unique opportunities for ultrafast device applications. While the physical behavior of FIMs near the compensation point has been widely studied, there lacks a generic understanding of FIMs where the ratio of sublattice spins can vary freely between the ferromagnetic and antiferromagnetic limits. Here we investigate the physical properties of a two-sublattice FIM manipulated by static magnetic fields and current-induced torques. By continuously varying the ratio of sublattice spins, we clarify how the dynamical chiral modes in a FIM are intrinsically connected to their ferro- and antiferromagnetic counterparts, which reveals unique features not visible near the compensation point. In particular, we find that current-induced torques can trigger spontaneous oscillation of the terahertz exchange mode. Compared with its realization in antiferromagnets, a spin-torque oscillator using FIMs not only has a reduced threshold current density but also can be self-stabilized, obviating the need for dynamic feedback.
Authors: Mingda Guo, Hantao Zhang, Ran Cheng
Institution: University of California, Riverside
Language: English
Subfield: Atomic and Molecular Physics, and Optics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
Award: G2284056879
OpenAlex ID: W3206877162