Spin polarization of quantum well states in Ag films induced by the Rashba effect at the surface

The electronic structure of Ag(111) quantum well films covered with a (root 3 x root 3) R30 degrees Bi/Ag surface ordered alloy, which shows a Rashba spin-split surface state, is investigated with angle-resolved photoemission spectroscopy. The band dispersion of the spin-split surface state is significantly modified by the interaction with the quantum well states of Ag films. The interaction is well described by the band hybridization model, which concludes the spin polarization of the quantum well states.