Jungiusstr. 11, Hörsaal AP
SFB 668 - Kolloquium
Dr. Christian Ast (MPI Stuttgart):
Strongly Enhanced Spin-Splitting in Two-Dimensional Electron Systems at Metallic and Semiconducting Surfaces
The Rashba-Bychkov (RB) model has been remarkably successful in describing the spin splitting of two-dimensional (2D) electron systems with a structural inversion asymmetry (SIA), which makes it one of the key mechanisms in the emerging field of spintronics for manipulating the electron spin without the use of magnetic fields. The Bi/Ag(111) surface alloy is a representative of a new class of materials, which exhibits a particularly large spin-splitting. However, only a fraction of the atoms in a surface alloy exhibit a large atomic spin-orbit interaction, so that a more detailed understanding of the underlying mechanism is necessary. We have transferred this concept onto a semiconducting surface, where we also identified a large spin-splitting in Bi/Si(111) .
These new systems with a particularly large spin-splitting question the dominant role of the atomic spin-orbit coupling and point towards a strong structural influence in the spin-splitting mechanism.