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O: Fachverband Oberflächenphysik

O 66: Poster Session V: 2D Materials: Electronic structure, excitations, etc. I

O 66.13: Poster

Wednesday, March 3, 2021, 10:30–12:30, P

Highly ordered metallic phase of Indium on SiC(0001) — •Jonas Erhardt, Maximilian Bauernfeind, Simon Moser, and Ralph Claessen — Physikalisches Institut and Würzburg-Dresden Cluster of Excellence ct.qmat, Universität Würzburg, Würzburg D-97074, Germany

Indium thin films attract attention due to diverse electronic properties, which feature for instance a two-dimensional electron gas (2DEG) [1] and superconductivity [2] in the 2D limit or Dirac-electrons in a triangular lattice [3]. Here, we present a combined angle-resolved photoelectron spectroscopy (ARPES) and scanning tunneling microscopy (STM) study of ultrathin (∼  2 monolayers) epitaxial indium films on silicon carbide (SiC). STM reveals a Kagome-like superstructure with a lattice constant of approximately 2.1   nm assigned as a (4√3 ×4√3)R30^∘ reconstruction. Additionally, ARPES as well as scanning tunneling spectroscopy (STS) show a metallic band structure with a pronounced electron pocket, indicative of a 2DEG. Interestingly, STS further reveals negative differential conductance, which is in contrast to the canonical interpretation of the dI/dV signal as local density of states and is possibly related to substrate effects.

[1] E. Rotenberg et al., Phys. Rev. Lett. 91, 246404 (2003).

[2] T. Zhang et al., Nat. Phys. 6, 104 (2010).

[3] M. Bauernfeind et al., (unpublished)