SFB 1170


    Quasi-particle interference on clean and magnetically doped Rashba surfaces: fcc(111)- vs. honeycomb lattices


    For the realization of spintronic device concepts reliable means of manipulating the electron spin are needed. Magnetic leads have often been employed, but using the Rashba effect which originates from the spin-orbit interaction may be more elegant, as it would allow the manipulation of the electron spin through electric rather than magnetic fields. Within this project we will perform investigations of the electronic properties of Rashba systems based on fcc(111) surfaces and honeycomb lattices by scanning tunneling spectroscopy and quasi-particle interference. In contrast to √ - 3 ×√ - 3 layers on fcc(111) substrates, where the Rashba term lifts the degeneracy of bands around the Γ-point of the surface Brillouin zone by a constant momentum offset, kso(E) = const, it has been predicted that the Rashba interaction in honeycomb systems leads to a splitting that is constant in energy, Δso(E) = const, around the K-point. We will investigate the validity of this prediction and study the impact of magnetic surface impurities and (ferro)magnetic substrates on coherent scattering processes. The combination of strong spin-orbit coupling with (ferro)magnetism may lead to a combined momentum- and energy-shift of the involved bands, resulting in highly complex spin topologies. Depending on the magnetization and the degree of spin-orbit interaction induced by the magnetic substrate various scenarios can be expected, the understanding of which will be highly valuable for future spintronics applications.