The spin texture of the metallic two-dimensional electron system (root3 x root3)-Au/Ge(111) is revealed by fully three-dimensional spin-resolved photoemission, as well as by density functional calculations. The large hexagonal Fermi surface, generated by the Au atoms, shows a significant splitting due to spin-orbit interactions. The planar components of the spin exhibit helical character, accompanied by a strong out-of-plane spin component with alternating signs along the six Fermi surface sections. Moreover, in-plane spin rotations towards a radial direction are observed close to the hexagon corners. Such a threefold-symmetric spin pattern is not described by the conventional Rashba model. Instead, it reveals an interplay with Dresselhaus-like spin-orbit effects as a result of the crystalline anisotropies.
@article{arxiv.1203.0520,
title = {Three-Dimensional Spin Rotations at the Fermi Surface of a Strongly Spin-Orbit Coupled Surface System},
author = {Philipp Hoepfner and Joerg Schaefer and Andrzej Fleszar and Jan Hugo Dil and Bartosz Slomski and Fabian Meier and Christoph Loho and Christian Blumenstein and Luc Patthey and Werner Hanke and Ralph Claessen},
journal= {arXiv preprint arXiv:1203.0520},
year = {2013}
}
Comments
5 pages, 4 figures, accepted at Physical Review Letters