title: Direct observation of interband spin-orbit coupling in a two-dimensional electron system.
abstract: We report the direct observation of interband spin-orbit (SO) coupling in a two-dimensional (2D) surface electron system, in addition to the anticipated Rashba spin splitting. Using angle-resolved photoemission experiments and first-principles calculations on Bi-Ag-Au heterostructures, we show that the effect strongly modifies the dispersion as well as the orbital and spin character of the 2D electronic states, thus giving rise to considerable deviations from the Rashba model. The strength of the interband SO coupling is tuned by the thickness of the thin film structures.
authors.affiliation: Experimentelle Physik VII and Röntgen Research Center for Complex Materials (RCCM), Universität Würzburg Am Hubland, D-97074 Würzburg, Germany.
authors.forename: Hendrik
authors.initials: H
authors.lastname: Bentmann
authors.forename: Samir
authors.initials: S
authors.lastname: Abdelouahed
authors.forename: Mattia
authors.initials: M
authors.lastname: Mulazzi
authors.forename: Jürgen
authors.initials: J
authors.lastname: Henk
authors.forename: Friedrich
authors.initials: F
authors.lastname: Reinert