Session A3: Electronic States in Graphene

8:00 AM–11:00 AM, Monday, March 5, 2007
Colorado Convention Center - Korbel 2A-3A

Sponsoring Unit: DCMP
Chair: Philip Kim, Columbia University

Abstract ID: BAPS.2007.MAR.A3.3

Abstract: A3.00003 : Electronic Confinement and Coherence in Patterned Epitaxial Graphene

9:12 AM–9:48 AM

Preview Abstract

Author:

  Claire Berger
    (GATECH-Atlanta / CNRS-France)

Transport in ultrathin graphite films grown on single-crystal silicon carbide is dominated by the electron-doped epitaxial graphene layer at the interface and shows graphene characteristics. Epitaxial graphene provides a platform for studying the novel electronic properties of this 2D electron gas in a controlled environment. Shubnikov-de Haas oscillations in the magnetoresistance data indicate an anomalous Berry's phase and reveal the Dirac nature of the charge carriers. The system is highly coherent with phase coherence lengths beyond 1 micrometer at cryogenic temperatures, and mobilities exceeding 2.5 square meters per volt-second. In wide structures, evidence is found for weak anti-localization in agreement with recent graphene weak-localization theory. Patterned narrow ribbons show quantum confinement of electrons. Several Hall bar samples reveal anomalous magnetoresistance patterns consisting of large structured non-periodic oscillations that may be due to a periodic superlattice potential.

To cite this abstract, use the following reference: http://meetings.aps.org/link/BAPS.2007.MAR.A3.3