Theory of circular dichroism in angle- and spin-resolved photoemission from the surface state on Bi(111)

Circular dichroism (CD) of photoemission from a surface state on Bi(111) is considered within an ab initio onestep theory of photoemission. The symmetry of the azimuthal distribution of CD for different spin directions is discussed in terms of the spin structure of the initial states. Both normal and off-normal light incidence are considered. Strong photon energy dependence of photoemission in the ultraviolet range is observed. The principal difference between the initial state spin polarization and the spin photocurrent is emphasized and problems with revealing the orbital angular moment with photoemission are pointed to.