Spin-polarization of the electric current in half-metallic Co$_2$MnSi Heusler thin films

Abstract

Using propagating spin wave spectroscopy we measure the spin wave Doppler shift in patterned MgO/Co$_2$MnSi/MgO thin films and determine the degree of spin-polarization of the electric current. Our measurements reveal that the current is fully spin-polarized in the devices. This shows that the half-metallic character of the electron band structure translates into a fully spin polarized current flowing across the patterned films. Additionally, we measure a current-induced change of the spin-wave attenuation from which we estimate the non-adiabatic spin-transfer-torque parameter.