Detection of Spin Hall effect in antiferromagnets with tunnel junctions

The Spin Hall Effect (SHE) utilizes spin-orbit coupling to convert electrical current into pure spin current, which can subsequently be employed to drive magnetic moment reversal or precession, manifesting as the spin-orbit torque (SOT) effect. The SHE originates from intrinsic spin-orbit coupling in materials, manifesting through three microscopic mechanisms: intrinsic mechanism dependent on band structure, extrinsic mechanisms side jump and skew scattering. Although researchers have recognized the potential of linking SHE with magnetic structures to amplify the former and have experimentally explored this relationship in magnetically ordered systems like ferromagnets(FM) and antiferromagnets(AFM), physically elucidating this connection remains challenging.

In this talk I will introduce progresses on the spin Hall effect tunneling spectroscopy (SHTS) [1-3] of AFMs. Combining tunnel junction with SHE, SHTS enables direct electrical observation of SHE, especially in materials with short spin diffusion lengths. The SHTS reveals how the SHE relates to the AFM order. Spin Hall angle is obviously tuned by more than 50% with the variation of AFM order. This variation of SHE as the temperature [4] or carrier energy[5] shed light on effective application of AFM in spintronic devices.

[1] L. Liu et al., Nat. Phys., 10 (2014) 561-566
[2] C. Fang et al., Phys. Rev. B, 96 (2017) 134421
[3] C. Fang et al., Nano Lett. , 23 (2023)11485–11492
[4] S. Okamoto et al., Phys. Rev. Lett., 123 (2019) 196603

[5] Y. Zhang et al., Phys. Rev. B, 95 (2017) 075128