Magneto-conductance Oscillations in Graphene Antidot Arrays

TL;DR

This paper reports on the observation of magneto-conductance oscillations in graphene antidot arrays, revealing quantum interference effects, weak localization, and classical cyclotron orbit commensurability, with features persisting up to 70 K.

Contribution

It demonstrates the presence of Aharonov-Bohm oscillations and other mesoscopic phenomena in graphene antidot arrays fabricated on SiC substrates, highlighting their unique electronic properties.

Findings

Aharonov-Bohm oscillations corresponding to flux quanta per antidot area

Enhanced weak localization due to intravalley scattering

Classical cyclotron orbit commensurability minima at high fields

Abstract

Epitaxial graphene films have been formed on the C-face of semi-insulating 4H-SiC substrates by a high temperature sublimation process. Nano-scale square antidot arrays have been fabricated on these graphene films. At low temperatures, magneto-conductance 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 intravalley 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.