Large spin Hall effect in sputtered thin film of non-collinear Mn₃Sn  anti-ferromagnet

The detection and manipulation of electron spin currents by the spin Hall effect (SHE) is a key focus in spintronics. The SHE was originally conceived as a relativistic spin-orbit coupling (SOC) based process by which electrical current generates transverse spin currents. In contrast, the intrinsic SHE arises from intrinsic properties of the band structure more specifically, from symmetries of the spin Berry curvature [1] and the latter is also closely relate to the Berry curvature responsible for the anomalous Hall effect (AHE). In the most general noncoplanar magnetic lattice, the time reversal and spin rotation symmetries are naturally broken. Hence, the SHE can exist without SOC in noncollinear magnetic lattices. This was first proposed and experimentally reported in antiferromagnetic (AFM) thin films of Mn₃Ir [2]. Recently, evidence of a large AHE has mounted for several non-collinear AFM systems including Mn₃Ge [3] and Mn₃Sn [4]. Thus, a significant SHE can be anticipated in these materials. In this work we report a large SHE in thin sputter-deposited films of Mn₃Sn. The observation of the SHE in light compounds as the Mn₃Sn marks another step towards the integration of the SHE in practical devices that exhibit low damping in a controllable manner.

[1]        Y. Zhang, J. Železný, Y. Sun, J. van den Brink, and B. Yan, "Spin Hall effect emerging from a noncollinear magnetic lattice without spin–orbit coupling", New Journal of Physics 20, 073028 (2018).

[2]        W. Zhang, W. Han, S.-H. Yang, Y. Sun, Y. Zhang, B. Yan, and S. S. P. Parkin, "Giant facet-dependent spin-orbit torque and spin Hall conductivity in the triangular antiferromagnet IrMn3", Science Advances 2 (2016).

[3]        A. K. Nayak, J. E. Fischer, Y. Sun, B. Yan, J. Karel, A. C. Komarek, C. Shekhar, N. Kumar, W. Schnelle, J. Kübler, C. Felser, and S. S. P. Parkin, "Large anomalous Hall effect driven by a nonvanishing Berry curvature in the noncolinear antiferromagnet Mn3Ge", Science Advances 2 (2016).

[4]        T. Ikeda, M. Tsunoda, M. Oogane, S. Oh, T. Morita, and Y. Ando, "Anomalous Hall effect in polycrystalline Mn3Sn thin films", Applied Physics Letters 113, 222405 (2018).