Dresden 2020 – scientific programme
The DPG Spring Meeting in Dresden had to be cancelled! Read more ...
Parts | Days | Selection | Search | Updates | Downloads | Help
O: Fachverband Oberflächenphysik
O 87: Poster Session - Nanostructures at Surfaces: 1D and 2D Structures and Networks
O 87.3: Poster
Wednesday, March 18, 2020, 18:15–20:00, P2/1OG
Epitaxial growth of Bi on epitaxial graphene — •Chitran Ghosal1, Johannes Aprojanz1, and Christoph Tegenkamp1,2 — 1TU Chemnitz, Germany — 2Leibniz Universität Hannover, Germany
The semimetal Bi still attracts a lot of interest because of its unique electronic properties such as a low carrier concentrations and large carrier mobilities. The mesocopic Fermi wavelength gives rise to pronounced quantum confinement effects, e.g the semimetal to semiconductor transition. The surface states on Bi(111) reveal strong spin polarization and ultrathin Bi films are topologically non-trivial. Therefore, proximity coupling of Bi nanostructures to graphene may be used to tune the transport properties of the 2D relativistic electron gas. In this work we studied the growth of the Bi on epitaxial graphene on SiC(0001) by means of LEED and STM. While for low coverages Bi(110) are formed, Bi(111) structures were found in the high coverage regime. This allotropic transition occurs around 14 bilayers (5.6 nm) and significantly larger than the transition reported on Si(111) [1]. Moreover, needle-like structures along three different directions were found. For various Bi coverages, the widths of these Bi-structures is around 12 nm, apparently, due to a lateral quantum confinement effect. Contrary, magic heights were now observed. In order to probe proximity effects, we will present also first magneto transport measurements. [1] T. Nagao, et al. Phys. Rev. Lett, 93, 105501 (2004).