Large Spin Anomalous Hall Effect in L1${}_0$-FePt: Symmetry and Magnetization Switching

Abstract

We quantitatively evaluate a spin anomalous Hall effect (SAHE), generating spin angular momentum flow (spin current, $J_{\mathrm{s}}$), in an L1${}_0$-FePt ferromagnet by exploiting giant magnetoresistance devices with L1${}_0$-FePt / Cu / Ni${}_{81}$Fe${}_{19}$ . From the ferromagnetic resonance linewidth modulated by the charge current ($J_{\mathrm{c}}$) injection, the spin anomalous Hall angle (${\alpha }_{\mathrm{SAH}}$) is obtained to be 0.25 $\pm$ 0.03. The evaluation of ${\alpha }_{\mathrm{SAH}}$ at different configurations between $J_{\mathrm{c}}$ and magnetization enables us to discuss the symmetry of SAHE and gives the unambiguous evidence that SAHE is the source of $J_{\mathrm{s}}$. Thanks to the large ${\alpha }_{\mathrm{SAH}}$, we demonstrate the SAHE-induced magnetization switching.

16 pages, 4 figures