Analytic Model for the Energy Spectrum of a Graphene Quantum Dot in a   Perpendicular Magnetic Field
  We analytically calculate the energy spectrum of a circular graphene quantum dot with radius R subjected to a perpendicular magnetic field B by applying the infinite-mass boundary condition. We can retrieve well-known limits for the cases R, B going to infinity and B going to zero. Our model is capable of capturing the essential details of recent experiments. Quantitative agreement between theory and experiment is limited due to the fact that a circular dot is not close enough to the experimental geometry, that disorder plays a significant role, and that interaction effects may be relevant. 
S. Schnez, K. Ensslin, M. Sigrist, and T. Ihn