Strong Rashba-Type Spin Polarization of the Photocurrent from Bulk Continuum States: Experiment and Theory for Bi(111)

Strong spin polarization of the photocurrent from bulk continuum states of Bi(111) is experimentally observed. On the basis of ab initio one-step photoemission theory the effect is shown to originate from the strong polarization of the initial states at the surface and to be the result of the surface sensitivity of photoemission. Final state effects cause deviations of the k(vertical bar vertical bar) dependence of polarization from strictly antisymmetric relative to (Gamma) over bar