Regensburg 2019 – scientific programme
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O: Fachverband Oberflächenphysik
O 18: Poster Monday: Nanostructures
O 18.8: Poster
Monday, April 1, 2019, 17:45–20:00, Poster F
Sn nanowires on a vicinal Si(111) surface — •Monika Jäger1, Herbert Pfnür1, Mauro Franciulli2, Andrew Weber2, Jan-Hugo Dil2, and Christoph Tegenkamp1,3 — 1Leibniz Universität Hannover, Germany — 2Swiss Light Source, Villigen, Switzerland — 3TU Chemnitz, Germany
The α-Sn phase on Si(111) is a prototype system for a two-dimensional Mott phase. Recently, the low temperature phase was investigated by means of spin-resolved ARPES showing that the formation of the row-wise collinear antiferromagnetically spin-ordering is accompanied by a small Rashba-splitting of the highest occupied Mott state [1].
In order to study the influence of confinement towards the Mott state we studied the growth of Sn-nanowires on vicinal Si(111) by means of STM and ARPES. Depending on the Sn coverage, three different phases were identified. At low coverages, the surface structure of Si(557) is preserved comprising 3 nm wide α-Sn stripes. They exhibit a metallic surface state in ARPES at low temperatures possibly due to doping of the Mott state via step edges. Similar observations of metallic QP states were reported for hole doped α-Sn/Si(111) [2]. Further increase of the coverage to 0.5 ML leads to a refacetting of the surface exhibiting locally a (223) orientation. The wider (111) terraces reveal both (√3×√3) and (2√3× 2√3) Sn reconstructions, the latter is well known for 0.3-1.2 ML Sn/Si(111). For higher coverages (>0.7 ML), step bunching sets in resulting in wide (2√3× 2√3)-domains.
[1] M. Jäger et al., PRB 98, 165422, (2018).
[2] F. Ming et al., PRL 119, 266802, (2017).