LandauLevel Splitting in Graphene in High Magnetic Fields
Abstract
The quantum Hall (QH) effect in twodimensional electrons and holes in high quality graphene samples is studied in strong magnetic fields up to 45 T. QH plateaus at filling factors ν=0,±1,±4 are discovered at magnetic fields B>20T, indicating the lifting of the fourfold degeneracy of the previously observed QH states at ν=±4(n+1/2), where n is the Landaulevel index. In particular, the presence of the ν=0,±1 QH plateaus indicates that the Landau level at the charge neutral Dirac point splits into four sublevels, lifting sublattice and spin degeneracy. The QH effect at ν=±4 is investigated in a tilted magnetic field and can be attributed to lifting of the spin degeneracy of the n=1 Landau level.
 Publication:

Physical Review Letters
 Pub Date:
 April 2006
 DOI:
 10.1103/PhysRevLett.96.136806
 arXiv:
 arXiv:condmat/0602649
 Bibcode:
 2006PhRvL..96m6806Z
 Keywords:

 73.63.b;
 73.21.b;
 73.43.f;
 Electronic transport in nanoscale materials and structures;
 Electron states and collective excitations in multilayers quantum wells mesoscopic and nanoscale systems;
 Quantum Hall effects;
 Condensed Matter  Mesoscopic Systems and Quantum Hall Effect;
 Condensed Matter  Strongly Correlated Electrons
 EPrint:
 11 pages including 4 figures, to appear in PRL