Electronic transmission and conductance oscillations in electrostatic multibarrier system based on graphene monolayer

Abstract

The Landauer-Buttiker formalism and the transfer matrix method (TMM) were used to solve the Dirac equation to theoretically explore the transmission coefficient and the conductance of multibarrier graphene systems (MGS). We have addressed the impact of the number of barriers, angle of incidence, and the quantum size of different layers on the electronic properties. The obtained results show that the conductance and the transmission of the carriers can be readily modulated by increasing the number of barriers. It has been observed that an increase in the number of barriers doubles the number of resonant states which leads to the emergence of energetic minibands alternating with minigaps. Furthermore, we found that after doubling the quantum wells the number of resonant states and minigaps increase and their shapes become well defined. Moreover, we considered two cases of incidence (oblique and normal). In the normal incidence case, the structures were completely transparent for different sizes and incident energy values. However, for high angles of incidence, the transmission coefficient presented sharper resonant peaks separated by minigaps. Thereby, according to our theoretical investigations, such structures can be useful for modulating the electronic properties of devices based on electrostatic MGS.