Stacking-Dependent Band Gap and Quantum Transport in Trilayer Graphene

W. Bao; L. Jing; Y. Lee; J. Velasco Jr.; P. Kratz; D. Tran; B. Standley; M. Aykol; S. B. Cronin; D. Smirnov; M. Koshino; E. McCann; M. Bockrath; C. N. Lau

doi:10.1038/nphys2103

arXiv · 1103.6088

Stacking-Dependent Band Gap and Quantum Transport in Trilayer Graphene

W. Bao·L. Jing·Y. Lee·J. Velasco Jr.·P. Kratz·D. Tran·B. Standley·M. Aykol·S. B. Cronin·D. Smirnov·M. Koshino·E. McCann·M. Bockrath·C. N. Lau

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Abstract

In a multi-layer electronic system, stacking order provides a rarely-explored degree of freedom for tuning its electronic properties. Here we demonstrate the dramatically different transport properties in trilayer graphene (TLG) with different stacking orders. At the Dirac point, ABA-stacked TLG remains metallic while the ABC counterpart becomes insulating. The latter exhibits a gap-like dI/dV characteristics at low temperature and thermally activated conduction at higher temperatures, indicating an intrinsic gap ~6 meV. In magnetic fields, in addition to an insulating state at filling factor ν=0, ABC TLG exhibits quantum Hall plateaus at ν=-30, \pm 18, \pm 9, each of which splits into 3 branches at higher fields. Such splittings are signatures of the Lifshitz transition induced by trigonal warping, found only in ABC TLG, and in semi-quantitative agreement with theory. Our results underscore the rich interaction-induced phenomena in trilayer graphene with different stacking orders, and its potential towards electronic applications.

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W. Bao, L. Jing, Y. Lee, J. Velasco Jr., P. Kratz, D. Tran, B. Standley, M. Aykol, S. B. Cronin, D. Smirnov, M. Koshino, E. McCann, M. Bockrath, C. N. Lau. 2012-01-20. Stacking-Dependent Band Gap and Quantum Transport in Trilayer Graphene. https://doi.org/10.1038/nphys2103

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