Fig. 2: Efficient orbital-to-spin conversion by rare-earth Gd with strong spin–orbit coupling.
From: Efficient conversion of orbital Hall current to spin current for spin-orbit torque switching
a Schematic illustration of the orbital-to-spin (L–S) conversion by \({{{\eta }}}_{{{{L}}} - {{{S}}}}^{{{{{\rm{Gd}}}}}}\) in the Cr/Gd heterostructure. The spin (orbital) angular momentum is represented by S (L). The source of S and L is marked by the subscript of SHE (OHE) for spin Hall effect (orbital Hall effect). b, c \({{{R}}}_{{{{xy}}}}^{2{{{\omega }}}}({{{\varphi }}})\) under different Bext of Gd (10 nm)/Cr (5 nm) (b) and Co (10 nm)/Cr (5 nm) (c) samples. Each \({{{R}}}_{{{{xy}}}}^{2{{{\omega }}}}({{{\varphi }}})\) of Gd/Cr (b) and Co/Cr (c) is shifted by a y-axis offset to clearly show Bext dependence. The solid lines are the fitting curves using Eq. (2). d \({{{R}}}_{{{{{{{{\rm{COS\varphi }}}}}}}}}^{2{{{\omega }}}}{{{{{{{\mathrm{/}}}}}}}}{{{R}}}_{{{{{{{{\rm{AHE}}}}}}}}}^{1{{{\omega }}}}\) versus 1/Beff of Gd/Cr (brown) and Co/Cr (blue-green) samples. Each solid line is the linear fitting line. All measurements are conducted at 10 K. The error bars in d are due to the standard deviation of the fitting of the \({{{R}}}_{{{{xy}}}}^{2{{{\omega }}}}({{{\varphi }}})\) versus φ curves using Eq. (2), which are smaller than the symbol size.
