Abstract
The electronic band structure of ABC-stacked multilayer graphene is studied within an effective mass approximation. The electron and hole bands touching at zero energy support chiral quasiparticles characterized by Berry’s phase for layers, generalizing the low-energy band structure of monolayer and bilayer graphene. We investigate the trigonal-warping deformation of the energy bands and show that the Lifshitz transition, in which the Fermi circle breaks up into separate parts at low energy, reflects Berry’s phase . It is particularly prominent in trilayers, , with the Fermi circle breaking into three parts at a relatively large energy that is related to next-nearest-layer coupling. For , we study the effects of electrostatic potentials which vary in the stacking direction, and find that a perpendicular electric field, as well as opening an energy gap, strongly enhances the trigonal-warping effect. In magnetic fields, the Lifshitz transition is manifested as a coalescence of Landau levels into triply degenerate levels.
- Received 25 June 2009
DOI:https://doi.org/10.1103/PhysRevB.80.165409
©2009 American Physical Society