Scattering of massless Dirac fermions in circular p-n junctions with and without magnetic field

Abstract

In the absence of a magnetic field, a scattered wavefunction inside a circular p-n junction in graphene exhibits an interference pattern with its high intensity maximum located around the caustics. We investigate the wavefunctions in the presence of a uniform magnetic field outside the circular region to show how the loci of the high intensity region changes by forming a Landau-level structure outside the circular region and a central high intensity region inside the circular p-n junction due to the strong reflection of massless Dirac fermions by the outside magnetic field. We conclude by suggesting experimental ways to detect such changes in pattern due to the effect of the magnetic field.