Dresden 2014 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

HL: Fachverband Halbleiterphysik

HL 76: Graphene: Electronic properties (organized by O)

HL 76.3: Vortrag

Mittwoch, 2. April 2014, 16:30–16:45, WIL C107

Exceptional ballistic transport in epitaxial graphene nanoribbonsJens Baringhaus1, Frederik Edler1, Claire Berger2, Walter A. de Heer2, and •Christoph Tegenkamp11Leibniz Universität Hannover, Institut für Festkörperphysik, 30167 Hannover, Germany — 2Georgia Institute of Technology, Atlanta, Georgia 30332-0430, USA

The patterning of graphene into graphene nanoribbons is an essential task for the development of graphene based devices. For such ribbons with a well-ordered edge geometry the presence of one-dimensional edge states has been predicted. We use a selective graphitization process on SiC-mesa structures to produce graphene nanoribbons with a width of 40 nm. The local electronic properties of the ribbons are investigated by means of a 4-tip STM. In combination with a SEM, the precise positioning of all four tips on the nanometer range is possible to perform local transport measurements. Additionally, local tunneling spectroscopy reveals characteristic features of ferromagnetic zig-zag graphene nanoribbons. Transport experiments carried out on the very same ribbon show a conductance close to e2/h for a wide temperature range from 30 K up to room temperature and probe spacings between 1 µm and 10 µ m. Description within the Landauer formalism is possible assuming ballistic transport dominated by a single channel. Transport in the second zeroth subband is only detectable for probe spacings smaller than 1 µ m due to the short localization length of carriers in this subband manifesting in the increase of the conductance to 2 e2/h at probe spacings below 200 nm.

100% | Mobil-Ansicht | English Version | Kontakt/Impressum/Datenschutz
DPG-Physik > DPG-Verhandlungen > 2014 > Dresden