Spin Hall and spin-orbit torque in ferromagnetic system

by Prof. Jia Zhang (张佳) (Huazhong University of Science and Technology)

Monday 17 Nov 2025, 10:30 → 11:30 Asia/Shanghai

Tsung-Dao Lee Institute/N4F-N400 - meeting room (Tsung-Dao Lee Institute)

Host: Prof. Liang Liu 

Venue: TDLI Meeting Room N400

Tencent meeting link:  https://meeting.tencent.com/dm/iMkMbb5cUd7a  

Meeting ID: 969193290, no password 

 

Abstract:

Spin Hall effect is pivotal phenomena in spintronics and condensed matter physics for “charge to spin” conversion. In “transition metal(TM)/ferromagnets (FM)” bilayers, the spin Hall effect is the leading mechanism for generating spin-orbit torque (SOT) and current induced switching of magnetization. In advanced memory devices, the field-free switching of perpendicular magnetization (PMA) requires spin current with out of plane spin polarization, which is lacking in conventional heavy metal like Pt, W, Ta etc. 

In this talk, we will first discuss two mechanisms for unconventional spin Hall effect in ferromagnets by employing first-principles calculations, including: (1) The spin-orbit coupling (SOC) induced magnetic spin hall effect in Fe, Co, Ni and their alloy. (2) The non-relativistic spin Hall effect originating from anisotropic longitudinal spin conductivity in L10-MnAl. We will also discuss the unconventional spin Hall effect in ferromagnets for field free switching of PMA. 

Recently, the orbital Hall effect (OHE), has attracted intensive research attention. It remains controversial and debated that how OHE may contribute to the spin torque in TM/FM bilayers. In the second part of the talk, we will discuss the calculation results on spin torque in TM/FM bilayers. The spin Hall, orbital Hall and self torque contributions to spin torque will be decomposed. 

 

References：

[1]. “Anatomy of the spin hall effect in ferromagnetic metals”, Phys. Rev. B. 109, 224401 (2024).

[2]. “Spin Hall effect in 3d ferromagnetic metals for field-free switching of perpendicular magnetization: A first-principles investigation”, Appl.Phys. Lett. 126, 092408 (2025).

[3].  “Inefficiency of orbital Hall effect on the spin torque in transition metal/ferromagnet bilayers”, Phys. Rev. Applied 24,034038 (2025).

 

Biography:

Jia Zhang, Professor in School of physics, Huazhong University of Science and Technology (HUST). He received his PhD at Institute of Physics, Chinese Academy of Sciences in 2012. During 2012 to 2016, he worked with Prof. Christian Heiliger and Evgeny Y. Tsymbal as postdocs. He joined HUST in 2016 as associated professor. His current research is focusing on the first-principles calculations and spin dynamics simulations on magnetic materials and their applications for spintronics devices. In the past few years his works on spin transport in ferromagnets and antiferromagnets have been published in scientific journals including Nature, Phys. Rev. Let., Nano Lett., Phys. Rev. B. etc.