Berlin 2018 – wissenschaftliches Programm

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O: Fachverband Oberflächenphysik

O 57: Electronic structure of surfaces: Spectroscopy, surface states II

O 57.7: Vortrag

Mittwoch, 14. März 2018, 12:15–12:30, MA 042

Spin-resolved ARPES measurements on Sn/Si(111) — •Monika Jäger¹, Herbert Pfnür¹, Mauro Franciulli², Andrew Weber², Jan-Hugo Dil², and Christoph Tegenkamp^1,3 — ¹Leibniz Universität Hannover, Germany — ²Swiss Light Source, Villigen, Switzerland — ³TU Chemnitz, Germany

In systems with spin-orbit coupling (SOC) and electronic correlations of comparable strength, like Pb/Si(557), a Spin-Orbit-Density-Wave is formed at low temperatures resulting in an insulating state below 78K [1]. It is characterized by Rashba-type spin-split bands with nesting between opposite helical states at the Fermi surface.
For Si(111) covered by 0.3 ML Sn, a √3×√3 reconstruction is formed which shows a Mott-type Metal-insulator transition upon cooling below 70 K [2]. Recently, this system was investigated by ARPES and DFT suggesting a collinear antiferromagnetic order with a 2√3×√3 spin cell at low temperatures [3].
Spin-resolved ARPES measurements reveal the existence of a spin-ordered surface unit cell larger than √3×√3. However, the SOC induced effects are small, thus the insulating state is mainly governed by electronic correlation effects.
[1] C. Brand et al., Nat. Comm. 6, 8118 (2015).
[2] S. Modesti et al., PRL 98, 126401 (2007).
[3] G. Li et al., Nat. Comm. 4, 1620 (2013).