title: Spin-flip transitions induced by time-dependent electric fields in surfaces with strong spin-orbit interaction.
abstract: We present a comprehensive theoretical investigation of the light absorption rate at a Pb/Ge(111)-β√3 × √3R30° surface with strong spin-orbit coupling. Our calculations show that electron spin-flip transitions cause as much as 6% of the total light absorption, representing 1 order of magnitude enhancement over Rashba-like systems. Thus, we demonstrate that a substantial part of the light irradiating this nominally nonmagnetic surface is attenuated in spin-flip processes. Remarkably, the spin-flip transition probability is structured in well-defined hot spots within the Brillouin zone, where the electron spin experiences a sudden 90° rotation. This mechanism offers the possibility of an experimental approach to the spin-orbit phenomena by optical means.
authors.affiliation: Materia Kondentsatuaren Fisika Saila, University of Basque Country UPV-EHU, 48080 Bilbao, Euskal Herria, Spain.
authors.forename: Julen
authors.initials: J
authors.lastname: Ibañez-Azpiroz
authors.forename: Asier
authors.initials: A
authors.lastname: Eiguren
authors.forename: E Ya
authors.initials: EY
authors.lastname: Sherman
authors.forename: Aitor
authors.initials: A
authors.lastname: Bergara