Quantum interference mapping of Rashba-split Bloch states in Bi/Ag(111)
L. El-Kareh, P. Sessi, T. Bathon, and M. Bode
Accepted
We report on low-temperature scanning tunneling spectroscopy (STS) investigations of the (3×3) Bi/Ag(111)R30 surface alloy surface which provides a giant Rashba-type spin-splitting. We observed spectroscopic features that are assigned to two Rashba-split bands. Quantum interference mapping shows that backscattering is not only allowed below but also above the Rashba energy. We argue that the observed behavior can be understood within the Bloch picture where k refers to the crystal momentum and the velocity of an electronic state is defined as vn(E) = \frac1(h/2p) kEn(k). The analysis of the energy dispersion of scattering channels reveals a conventional Rashba splitting for the unoccupied Rashba bands, while hybridization is observed in the occupied states.