Stacking-Dependent Band Gap and Quantum Transport in Trilayer Graphene
  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 {\nu}=0, ABC TLG exhibits quantum Hall plateaus at {\nu}=-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. 
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...
cond-mat.mes-hall cond-mat.mtrl-sci cond-mat.str-el