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Yu-Hui Tang

Publications and source records attributed to Yu-Hui Tang.

2 recordsLinked to original sources

Spin-Orbit Torque and Magnetization Switching in 2D Ferromagnetic Devices

Current-induced spin-orbit torque has emerged as a powerful technique for manipulating magnetization switching of ferromagnet/nonmagnet (FM/NM) based memory cell. By investigating nonequilibrium spin torque effect in a van der Waals heterobilayer, trigonal $\text{Cr}_{3}\text{Te}_{4}/\text{PtTe}_{2}$, the first-principles quantum transport calculations are applied to determine both local spin induction, resulting from Rashba-Edelstein effect in the FM layer, and spin current injection, flowing from the NM to the FM layer. Our work reveals that local spin induction significantly generates the fieldlike torque, which primarily governs the switching current in systems with strong in-plane magnetic anisotropy. Our work emphasizes the importance of optimizing spin Hall effect in the NM layer for perpendicular magnetic anisotropy (PMA)-based magnetization switching and maximizing the Rashba effect in the FM layer for in-plane magnetic anisotropy (IMA)-based switching.

cond-mat.mes-hall

Determining Perpendicular Magnetic Anisotropy in Fe/MgO/Fe Magnetic Tunnel Junction: A DFT-Based Spin-Orbit Torque Method

In our JunPy package, we have combined the first-principles calculated self-consistent Hamiltonian with divide-and-conquer technique to successfully determine the magnetic anisotropy (MA) in an Fe/MgO/Fe magnetic tunnel junction (MTJ). We propose a comprehensive analytical derivation to clarify the crucial roles of spin-orbit coupling that mediates the exchange and spin-orbit components of spin torque, and the kinetic and spin-orbit components of spin current accumulation. The angular dependence of cumulative spin-orbit torque (SOT) indicates a uniaxial MA corresponding to the out-of-plane rotations of magnetic moments of the free Fe layers. Different from the conventional MA energy calculation and the phenomenological theory for a whole MTJ, our results provide insight into the orbital-resolved SOT for atomistic spin dynamics simulation in emergency complex magnetic heterojunctions.

cond-mat.mtrl-sci