Thermal-annealing-induced symmetry breaking enables field-free spin-orbit-torque switching of a perpendicular ferrimagnet
Phys. Rev. Applied 25, 044015 – Published 7 April, 2026
DOI: https://doi.org/10.1103/xbwg-x8gp
Abstract
Current-induced spin-orbit torque (SOT) offers a promising approach for manipulating perpendicular magnetization in spintronic devices, enabling low-power and ultrafast applications. However, deterministic SOT switching typically requires an external in-plane magnetic field to break symmetry, complicating high-density device integration. Here, we demonstrate field-free SOT switching in the perpendicular ferrimagnet CoGd by inducting tilted magnetic anisotropy (TMA) via thermal annealing under an in-plane magnetic field. The TMA’s tilt angle is tunable by adjusting the annealing field strength, allowing deterministic switching when the in-plane TMA component aligns with the spin-polarization direction. This method leverages the low stray field, ultrafast spin dynamics, and high operation frequencies of ferrimagnet, offering a scalable solution for advanced spintronic devices.