Retrieving the initial-state spin polarization from spin-resolved photoemission: Proposal for a case study on W(110)

Abstract

Spin- and angle-resolved photoelectron spectroscopy is commonly used to determine the spin texture of the occupied electronic states. If spin-orbit coupling is strong, the spin polarization of the photoelectrons and that of the initial states may deviate significantly. To alleviate part of this problem we propose a recipe for improved spin retrieval. The basic idea is to combine photoemission intensities from (at least) two different photoemission experiments in a way which reflects the symmetry of the photoemission setups; the procedure avoids group-theoretical analyses or relativistic photoemission calculations. In this paper we introduce the approach, motivated by the example of photoemission from W(110) illuminated by circularly polarized light. Limitations of the method are discussed.