ECE Seminar   - Symmetry-based pure spin current origin classfication

Spin current and the related spin-orbit torque are crucial for spintronic applications, including magnetic random access memory and spin current logic devices. Various methods have been reported to generate pure spin current, including the spin Hall effect, Rashba-Edelstein effect, spin splitting effect etc. Typically, these mechanisms induced phenomena are very similar making it difficult to distinguish them.

In this talk, I will present systematic methods to distinguish different spin-charge conversion mechanisms based on the symmetry analysis and the reciprocal relation of the spin-charge inter-conversion. We identified the Rashba-Edelstein effect in Ag/Bi-ferromagnetic metal interface and solved the debate about the spin transport picture in Ag/Bi related systems [1], isolated the anisotropic spin Hall effect and spin splitting effect contributions in RuO2 [2], observed the anamolus spin Hall effect in Py and realized field-free switching of perpendicularly magnetized YIG with the z-polarized spin current [3]. The classification of different mechanisms may provide opportunity to enhance the efficiency of pure spin current generation and related spintronics devices.

[1] J. Cheng et. al., Phys. Rev. Lett. 129, 097203 (2022)

[2] Z. Q. Wang et. al., Phys. Rev. Lett. 133, 046701 (2024)

[3] M. Yang et.al., Nat. Commun. 15, 3201 (2024)