Two-Dimensional Quantum ring in a Graphene Layer in the presence of a Aharonov-Bohm flux

In this paper we study the relativistic quantum dynamics of a massless fermion confined in a quantum ring. We use a model of confining potential and introduce the interaction via Dirac oscillator coupling, which provides ring confinement for massless Dirac fermions. We obtain the energy levels and corresponding eigenfuctions for this model in graphene layer in the presence of Aharonov-Bohm flux in the centre of the ring and the expression for persistent current in this model. We also investigate the model for quantum ring in graphene layer in the presence of disclination and magnetic flux. The energy spectrum and wave function are obtained exactly for this case. We see that the persistent current depends in parameters characterizing the topological defect.