Anomalous spin current anisotropy in a noncollinear antiferromagnet
Cuimei Cao, Shiwei Chen, Rui‐Chun Xiao, Zengtai Zhu, Guoqiang Yu, Yangping Wang, Xuepeng Qiu, Liang Liu, Tieyang Zhao, Ding‐Fu Shao, Yang Xu, Jingsheng Chen, Qingfeng Zhan
Abstract
Abstract Cubic materials host high crystal symmetry and hence are not expected to support anisotropy in transport phenomena. In contrast to this common expectation, here we report an anomalous anisotropy of spin current can emerge in the (001) film of Mn 3 Pt, a noncollinear antiferromagnetic spin source with face-centered cubic structure. Such spin current anisotropy originates from the intertwined time reversal-odd ( $${{{{{\mathscr{T}}}}}}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mi>T</mml:mi> </mml:math> -odd) and time reversal-even ( $${{{{{\mathscr{T}}}}}}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mi>T</mml:mi> </mml:math> -even) spin Hall effects. Based on symmetry analyses and experimental characterizations of the current-induced spin torques in Mn 3 Pt-based heterostructures, we find that the spin current generated by Mn 3 Pt (001) exhibits exotic dependences on the current direction for all the spin components, deviating from that in conventional cubic systems. We also demonstrate that such an anisotropic spin current can be used to realize low-power spintronic applications such as the efficient field-free switching of the perpendicular magnetizations.