Spin-Hall angle: θ_SH = σ_SH / σ_xx — charge-to-spin-current conversion efficiency

Spin-Hall angle θ_SH is a dimensionless material figure of merit for charge-to-spin-current conversion: θ_SH = σ_SH / σ_xx, i.e. the ratio of the spin-Hall conductivity to the longitudinal (charge) conductivity. Values span four orders of…