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arXiv · 2412.18937

Unveiling the nonrelativistic spin current polarization in an altermagnet

Chang Pan·Shuai Hu·Fanli Yang·Dongchao Yang·Weijia Fan·Zhong Shi·Liqing Pan·Shiming Zhou·Xuepeng Qiu
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Abstract

Spin current plays a central role in spintronics for driving exotic spin-dependent phenomena and high-performance device applications. Recently, a magnetic spin Hall effect has been discovered in spin-split antiferromagnets including noncollinear antiferromagnets and altermagnets, allowing the efficient generation of unconventional spin currents even in the absence of spin-orbit coupling. However, although such nonrelativistic spin currents are proposed to have a magnetic origin, the direct connection between the Neel vector and the spin current polarization is still missing. Here, using the altermagnetic RuO2 as a representative example, we unveil the spin current polarization by disentangling the conventional and magnetic spin Hall effects using a technique we developed based on the spin Hall magnetoresistance measurement. The results suggest that the nonrelativistic spin current hosts a polarization very close to the Neel vector. Our work offers unambiguous evidence of the magnetic origin of the nonrelativistic spin current in altermagnetic RuO2, and paves a straightforward route to understand the unconventional spin currents that are crucial in spintronics.

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Chang Pan, Shuai Hu, Fanli Yang, Dongchao Yang, Weijia Fan, Zhong Shi, Liqing Pan, Shiming Zhou, Xuepeng Qiu. 2024-12-25. Unveiling the nonrelativistic spin current polarization in an altermagnet. https://arxiv.org/abs/2412.18937

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