Spin-Flip Transitions Induced by Time-Dependent Electric Fields in Surfaces with Strong Spin-Orbit Interaction

摘要

We present a comprehensive theoretical investigation of the light absorp_Tion rate at a Pb/Ge(l11) -β3~(1/2) × 3R3O°~(1/2) surface with strong spin-orbit coupling. Our calculations show that electron spin-flip transitions cause as much as 6% of the total light absorp_Tion, 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.