Spin-flip diffusion length in 5d transition metal elements: a first-principles benchmark

Abstract

Little is known about the spin-flip diffusion length $l_{\mathrm{sf}}$, one of the most important material parameters in the field of spintronics. We use a density-functional-theory based scattering approach to determine values of $l_{\mathrm{sf}}$ that result from electron-phonon scattering as a function of temperature for all 5d transition metal elements. $l_{\mathrm{sf}}$ does not decrease monotonically with the atomic number Z but is found to be inversely proportional to the density of states at the Fermi level. By using the same local current methodology to calculate the spin Hall angle ${\Theta }_{\mathrm{sH}}$ that characterizes the efficiency of the spin Hall effect, we show that the products $\rho (T)l_{\mathrm{sf}}(T)$ and ${\Theta }_{\mathrm{sH}}(T)l_{\mathrm{sf}}(T)$ are constant.

Accepted for publication in Physical Review Letters