ON THE QUANTUM HALL EFFECT IN GRAPHENE

摘要

The unusual quantum Hall effect (QHE) in graphene is often discussed in terms of Dirac fermions moving with a linear dispersion. A new theory describing the same phenomena is presented in terms of the more traditional composite bosons. The "electron" (wave packet) is shown to move easier in the direction [110] [110 c-axis] of the honeycomb lattice than perpendicular to it, while the "hole" moves easier in [001]. Since "electrons" and "holes" move in different channels, the number densities can be very high especially when the Fermi surface has "necks". The strong QHE at filling factor v = 2 arises from the "neck" Fermi surfaces.