Coulomb potential effects on spectra of graphene magnetic quantum dots.

The low-lying spectra of hydrogenic impurities in magnetic quantum dots of graphene are calculated numerically from the Dirac-Weyl equation. The positive and negative energy states are attracted and repelled, respectively, by the impurities. The zero-energy level is nondegenerate and its corresponding states split by the Coulomb potential into hole-like states. Modulation effects of the Coulomb potential on the spectra are explored by varying magnetic field and dot size. These behaviors can be confirmed by the corresponding electron probability densities and binding energies, which can be tested in future experiments. [ABSTRACT FROM AUTHOR]