Extracting the Rashba splitting from scanning tunneling microscopy measurements

The Rashba-type spin-splitting found in many two-dimensional electron systems at surfaces is a band splitting in momentum, which is most easily extracted from angular resolved photoemission data. Scanning tunneling microscopy as a real-space resolving technique relies on quasiparticle interference to extract momentum information about the experimental electronic structure. However, the lifted spin degeneracy in the Rashba split bands imposes a selection rule that makes it impossible to extract the Rashba splitting from single scattering events, e.g. scattering from a point defect in STM data. Nevertheless, going beyond single scattering events, the Rashba-type spin splitting can be extracted from STM data, which will be discussed in this review.