Thin line of a Rashba-type spin texture: Unoccupied surface resonance of Tl/Si(111) along Γ¯ M¯

Stolwijk Sebastian D., Sakamoto Kazuyuki, Schmidt Anke B., Krüger Peter, Donath Markus

Research article (journal)

Abstract

© 2014 American Physical Society. The Tl/Si(111)-(1×1) surface features outstanding properties with a unique spin pattern in momentum space. Along Γ¯K¯ (Γ¯K¯′), surface states with rotating spin had been observed. Here, the focus is put on the unoccupied surface electronic structure along the Γ¯M¯ high-symmetry direction. Spin- and angle-resolved inverse-photoemission experiments with sensitivity to the in-plane and out-of-plane components of the spin-polarization vector are conducted with the help of our recently developed rotatable spin-polarized electron source (ROSE). In agreement with our theoretical findings, we identify a surface resonance with giant spin-orbit-induced spin splitting, which exhibits an exclusive Rashba-type spin texture, i.e., a pure in-plane spin polarization perpendicular to Γ¯M¯, in compliance with the mirror-plane symmetry of the Γ¯M¯ direction. Notably, for slight deviations from the high-symmetry line, this constraint is lifted and additional spin-polarization components emerge. This highlights the importance of a correct alignment of the experiment when investigating samples with spin textures that are more complex than in simple Rashba systems or in ferromagnets.

Details zur Publikation

Release year: 2014
Language in which the publication is written: English