Single Dirac-cone state and quantum Hall effects in a honeycomb structure
Department of Applied Physics, University of Tokyo - Hongo 7-3-1, 113-8656, Japan
Received: 10 August 2013
Accepted: 16 October 2013
A honeycomb lattice system has four types of Dirac electrons corresponding to the spin and valley degrees of freedom. We consider a state that contains only one type of massless electrons and three types of massive ones, which we call the single Dirac-cone state. We analyze quantum Hall (QH) effects in this state. We make a detailed investigation of the Chern and spin-Chern numbers. We make clear the origin of unconventional QH effects discovered in graphene. We also show that the single Dirac-cone state may have arbitrary large spin-Chern numbers in magnetic field. Such a state will be generated in antiferromagnetic transition-metal oxides under electric field or in silicene with antiferromagnetic order under electric field.
PACS: 73.43.-f – Quantum Hall effects / 73.43.Cd – Theory and modeling / 81.05.ue – Graphene
© EPLA, 2013