Inverse Spin Hall Effect in the Normal and Ferromagnetic Metal
Ssu-Yen Huang1*
1Department of Physics, National Taiwan University, Taipei, Taiwan
* presenting author:Ssu-Yen Huang,
Recently, intense attention has focused on the generation, detection, and exploitation of pure spin current. Only a few mechanisms, among them the spin Hall effect, lateral spin valve, spin pumping and spin Seebeck effect (SSE), can generate a pure spin current. In the longitudinal SSE geometry, we have observed unusual transport phenomena, including a new type of magnetoresistance (MR) and anomalous Hall effects (AHE), in nominally nonmagnetic metals (Pt) thin films in contact with ferromagnetic insulator yttrium iron garnet (YIG). Through tuning the YIG surface, we are able to demonstrate the contributions of magnetic proximity effect of the new hybrid MR and AHE. To date, the inverse spin Hall effect (ISHE) has been observed only in non-magnetic metals, such as Pt and Au, with a strong spin-orbit coupling. We report the observation of ISHE in a ferromagnetic metal of permalloy (Py) on YIG by SSE and spin pumping. Through controlling the spin current injection by altering the Py/YIG interface, we have isolated the spin current contribution and first demonstrated the large ISHE in a 3d ferromagnetic metal. A large spin Hall angle in Py has been determined from Py thin films of different thicknesses. This indicates many other ferromagnetic metals, in addition to non-magnetic ones, may be exploited as superior pure spin current detectors and for applications in spin current phenomena.

Keywords: spin Hall effect, Inverse spin Hall effect, spin Seebeck effect