Ab initio calculation of intrinsic spin Hall conductivity of Pd and Au

Abstract

An ab initio relativistic band structure calculation of spin Hall conductivity (SHC) ( xy z) in Pd and Au metals has been performed. It is found that at low temperatures, intrinsic SHCs for Pd and Au are, respectively, ∼1400 and ∼400 (e) ( cm)-1. The large SHC in Pd comes from the resonant contribution from the spin-orbit splitting of the doubly degenerated 4d bands near the Fermi level at symmetry and X points, and the smaller SHC in Au is due to the broad free-electron-like 6s6p bands. However, as the temperature increases, the SHC in Pd decreases monotonically and reduces to ∼330 (e) ( cm)-1 at 300 K, while the SHC in Au increases steadily and reaches ∼750 (e) ( cm)-1 at room temperature. This indicates that the gigantic spin Hall effect [ xy z ≈ 105 (e) ( cm)-1] observed recently in the AuFePt system [T. Seki, Nature Mater. 7, 125 (2008)] is due to the extrinsic mechanisms such as the skew scattering by the impurities in Au. © 2009 American Institute of Physics.