Spin Polarization and Dichroism Effects by Electric Field

We show that electric field can induce spin polarization and dichroism effects in angle resolved photoemission spectroscopy (ARPES) in spin orbit coupling systems. The physical origin behind the effects essentially is the same as the spin Hall effect induced by the electric field. Since the ARPES experiments have both energy and momentum resolutions, the spin Hall effect can be directly verified by the ARPES experiments for individual band even if there is no net spin current.