Effective medium model for graphene superlattices with electrostatic and magnetic vector potentials

In this article we develop an effective medium model to characterize the electron wave propagation in graphene based nanostructures with electrostatic and magnetic vector potentials imposed on their surface. We use a numerical algorithm to determine the effective medium parameters of the heterostructure and calculate the electronic band structure of the system. We apply our formalism to analyze superlattices with solely a magnetic potential and reveal that the response of the structure remains reciprocal and is characterized by a decrease in the velocity of the charge carriers. We also study the response of superlattices with both potentials superimposed on graphene and show that the response of the system becomes nonreciprocal with a dispersion characterized by a tilted Dirac cone. We demonstrate that it is possible to alternate between type-I, type-II, or type-III Dirac cones by properly tuning the amplitude of the potentials.

Automated summary

In this article, we present an effective medium model for the electron wave propagation in graphene-based nanostructures with imposed electrostatic and magnetic vector potentials. We determine the effective medium parameters using a numerical algorithm and calculate the electronic band structure of the heterostructure. We demonstrate that superlattices with solely a magnetic potential exhibit a reciprocal response characterized by a decrease in charge carrier velocity, while superlattices with both potentials show a nonreciprocal response with a tilted Dirac cone dispersion. We also show the possibility of alternating between different types of Dirac cones by tuning the potentials' amplitudes.