Quantum tunneling mechanisms in monolayer graphene modulated by multiple electrostatic barriers

Abstract

The transmission coefficient and electronic conductance of a graphene monolayer modulated by multi-electrostatic barriers are theoretically investigated with the transfer matrix method (TMM). The transmission coefficient, conductance, and Fano factor are evaluated as a function of the number and width of the barriers, angle/energy of incidence, as well as the applied potential at each barrier. We find that the transmission coefficient exhibits a series of resonances that depends on the number and widths of the barriers. Furthermore, we show that the resonant states can be suppressed for larger incidence angles and barrier widths and tuned towards lower energies. Consequently, the proposed modifications in graphene can be used to tailor new optoelectronic devices based on (ON/OFF) states for use in tunable field-effect transistors.