Size Quantization in Planar Graphene-Based Heterostructures: Pseudospin   Splitting, Interface States, and Excitons
  A planar quantum-well device made of a gapless graphene nanoribbon with edges in contact with gapped graphene sheets is examined. The size-quantization spectrum of charge carriers in an asymmetric quantum well is shown to exhibit a pseudospin splitting. Interface states of a new type arise from the crossing of dispersion curves of gapless and gapped graphene materials. The exciton spectrum is calculated for a planar graphene quantum well. The effect of an external electric field on the exciton spectrum is analyzed. 
P. V. Ratnikov and A. P. Silin (Lebedev Physical Institute, Russian   Academy of Sciences)
cond-mat.mes-hall cond-mat.other