We present a reproducible computational framework to investigate quantum confinement and transport in circular graphene p–n junctions using the Kwant package. The system consists of a finite circular graphene flake under a smooth electrostatic potential described by a hyperbolic tangent profile, forming a continuous p–n interface. Two non collinear semi-infinite graphene leads enable current injection and extraction. We compute the eigenvalue spectra, density of states, local density of states, and two-terminal conductance. The framework incorporates a perpendicular magnetic field through the Peierls phase, allowing analysis of magneto-confinement and Landau-like resonances. We further derive semiclassical confinement conditions from the Dirac equation, linking analytic estimates to numerical eigenstates. All simulations and figures are generated in a headless Python environment, ensuring full reproducibility. This work highlights the interplay between smooth electrostatic potentials, magnetic quantization, and finite size confinement in graphene nanostructures.
Yohannes Achenefe Nigusie (Sun,) studied this question.