Ab initio spin-resolved photoemission and electron pair emission from a Dirac-type surface state in W(110)

Abstract

The spin texture of a Dirac-type surface state in W(110) lends itself to study spin-dependent effects in electron spectroscopies that show up very clearly. Firstly, we report on spin-resolved photoemission calculations and separate the spin polarization that is attributed to the initial state from that induced by the photoemission process itself. This disentanglement allows one to map spin textures of spin-polarized initial states using circular dichroism, for example from Dirac surface states in topological insulators. Secondly, we demonstrate the mapping of spin-polarized states by spin-dependent two-electron emission. Selecting highly polarized initial states, this spectroscopy can furthermore probe the spin dependence of the exchange-correlation hole.