  We demonstrate that a giant spin Hall effect (SHE) can be induced by
introducing a small amount of Bi impurities in Cu. Our analysis based on a new
3-dimensional finite element treatment of spin transport shows that the sign of
the SHE induced by the Bi impurities is negative and its spin Hall (SH) angle
amounts to -0.24. Such a negative large SH angle in CuBi alloys can be
explained by applying the resonant scattering model proposed by Fert and Levy
[Phys. Rev. Lett. 106, 157208 (2011)] to 6p impurities.
