Feasibility of measuring surface electron spin dynamics by inelastic scattering of metastable helium atoms

The application of inelastic scattering of monoenergetic beams of metastable (Formula presented) helium atoms (Formula presented) from surfaces of magnetic insulators to study the dynamical properties of surface electron-spin systems is considered. The study is based on a calculation of the differential inelastic reflection coefficient for magnetic scattering using a distorted-wave Born approximation approach. The NiO(001) surface is used as an example. The adiabatic scattering potential as well as the exchange coupling between a metastable He atom and the surface electron spins are determined by a configuration interaction calculation for an embedded NiO cluster model. The efficiency of measuring an inelastic magnetic event based on this calculation is estimated to be (Formula presented).