Chiral-spin rotation of non-collinear antiferromagnet by spin-orbit torque
Takeuchi, Yutaro*; Yamane, Yuta*; Yoon, J.-Y.*; Ito, Ryuichi*; Jinnai, Butsurin*; Kanai, Shun*; Ieda, Junichi
; Fukami, Shunsuke*; Ohno, Hideo*
Electrical manipulation of magnetic materials by current-induced spin torque constitutes the basis of spintronics. Recent studies have demonstrated electrical controls of ferromagnets and collinear antiferromagnets by spin-orbit torque (SOT). Here we show an unconventional response to SOT of a non-collinear antiferromagnet, which has recently attracted great attention owing to large anomalous Hall effect despite vanishingly small net magnetization. In heterostructures with epitaxial non-collinear antiferromagnet Mn
Sn, we observe a characteristic fluctuation of Hall resistance, which is attributed to a persistent rotation of chiral-spin structure of Mn
Sn driven by SOT. We find that level of the fluctuation that varies with sample size represents the number of magnetic domains of Mn
Sn. In addition, Mn
Sn thickness dependence of critical current reveals that SOT generated by small current density below 20 MA cm
effectively acts on the chiral-spin structure even in thick Mn
Sn above 20 nm. The results provide unprecedented pathways of electrical manipulation of magnetic materials, offering new-concept spintronics devices with unconventional functionalities and low-power consumption.