Quantum Tunneling Mechanisms in Monolayer Graphene Modulated by Multiple Electrostatic Barriers

The transmission coefficient and electronic conductance of a graphene monolayer in the presence of multi-electrostatic barriers are theoretically investigated using 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 presents 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 structure can be used to fabricate new optoelectronic devices based on (ON/OFF) states as tunable field-effect transistors.