Berlin 2024 – wissenschaftliches Programm

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O: Fachverband Oberflächenphysik

O 95: Electronic Structure of Surfaces II: Spectroscopy, Surface States

O 95.7: Vortrag

Donnerstag, 21. März 2024, 16:30–16:45, MA 144

Unusual Behavior of the Spin-Split L-Gap Surface Resonance at Pt(111) — •Fabian Schöttke, Peter Krüger, and Markus Donath — Universität Münster, Germany

We investigate the unoccupied electronic structure of Pt(111) with focus on the surface resonance (SR) at the bottom of the L gap. SR is discussed in the literature to be either typically free-electron like or hybridized with bulk states [1]. With different approaches within density-functional theory, we demonstrate that the lattice constant is crucial for the energetic position and dispersion behavior of SR. For experimentally obtained structural parameters as derived from low-energy electron diffraction studies [2], the hybridization-induced shape of SR results. In the case of hybridization, close to Γ, a downward dispersing branch of SR splits off with predominantly one spin direction. This behavior is a distinct deviation of the usual parabolic upward dispersing L-gap surface states. By spin- and angle-resolved inverse photoemission, we measure the dispersion of SR in close vicinity to Γ and find a scenario of spin-split spectral features in agreement with the aforesaid theoretical results. Furthermore, we elucidate how the position of SR at the bottom of the L gap leads to hybridization with the d bands in comparison with L-gap surface states/resonances at other fcc(111) surfaces [3].

[1] A. Dal Corso, Surface Science 637-638, 106 (2015).

[2] L. Hammer, T. Kißlinger, A. Schneider, private communication.

[3] Braun & Donath, Europhys. Lett. 59, 592 (2002).

Keywords: Pt(111); Inverse Photoemission; Surface State; Spin-Orbit Interaction; Hybridization