Determining the spin-orbit coupling via spin-polarized spectroscopy of magnetic impurities

Abstract

We study the spin-resolved spectral properties of the impurity states associated to the presence of magnetic impurities in two-dimensional, as well as one-dimensional systems with Rashba spin-orbit coupling. We focus on Shiba bound states in superconducting materials, as well as on impurity states in metallic systems. Using a combination of a numerical T-matrix approximation and a direct analytical calculation of the bound state wave function, we compute the local density of states (LDOS) together with its Fourier transform (FT). We find that the FT of the spin-polarized LDOS, a quantity accessible via spin-polarized STM, allows to accurately extract the strength of the spin-orbit coupling. Also we confirm that the presence of magnetic impurities is strictly necessary for such measurement, and that non-spin-polarized experiments cannot have access to the value of the spin-orbit coupling.