Magnetoconductance oscillations in graphene antidot arrays

T Shen, Purdue University
Y Q. Wu, Birck Nanotechnology Center, Purdue University
Leonid P. Rokhinson, Birck Nanotechnology Center, Purdue University
L W. Engel, National High Magnetic Field Laboratory
P. D. Ye, Birck Nanotechnology Center and School of Electrical and Computer Engineering, Purdue University

Abstract

Epitaxial graphene films have been formed on the C-face of semi-insulating 4H-SiC substrates by a high temperature sublimation process. Nanoscale square antidot arrays have been fabricated on these graphene films. At low temperatures, magnetoconductance in these films exhibits pronounced Aharonov-Bohm oscillations with the period corresponding to magnetic flux quanta added to the area of a single antidot. At low fields, weak localization is observed and its visibility is enhanced by intervalley scattering on antidot edges. At high fields, we observe two distinctive minima in magnetoconductance, which can be attributed to commensurability oscillations between classical cyclotron orbits and antidot array. All mesoscopic features, surviving up to 70 K, reveal the unique electronic properties of graphene. (C) 2008 American Institute of Physics.