Quantum Hall ferromagnetism in graphene.
Graphene is a two-dimensional carbon material with a honeycomb lattice and Dirac-like low-energy excitations. When Zeeman and spin-orbit interactions are neglected, its Landau levels are fourfold degenerate, explaining the 4e2/h separation between quantized Hall conductivity values seen in recent experiments. In this Letter we derive a criterion for the occurrence of interaction-driven quantum Hall effects near intermediate integer values of e2/h due to charge gaps in broken symmetry states.
Nomura
Kentaro
K
Department of Physics, University of Texas at Austin, Austin, Texas 78712-1081, USA.
MacDonald
Allan H
AH