Calculation of current density for graphene superlattice in a constant electric field

Abstract

Based on the transfer-matrix method, this paper has investigated the electrical transport properties in monolayer and bilayer graphene superlattices modulated by a homogeneous electric field. It is found that the angular range of the transmission probability can be efficiently controlled by the number of barriers. In addition, current density has an oscillatory behavior with respect to external field and Fermi energy. In other words, the current density in monolayer and bilayer graphene superlattices can be controlled by changing either the external field or the Fermi energy. Meanwhile, in the bilayer system unlike monolayer structure the value of current density can be zero. So, for designing electronic devices, bilayer graphene is more efficient.

Literature Review

“…These fermions are not affected by any external electrostatic potentials and exhibit Klein Paradox. They also exhibit integer quantum Hall effect through which the chances of electrons crossing a potential barrier is always one (Bolotin et al 2008;Neto et al 2009;Sattari 2015). The incident Dirac electrons do not get reflected and propagate with an efficiency of 100%, in cases where the internal scattering phenomenon and symmetrical aspects of carbon atoms are being neglected.…”

The Effect of the Asymmetry in the Transport through a Graphene-Based Quantum Structure in Uniform Electric Field

“…Concerning the biased structures, the resonant tunneling has been studied for a double barrier structure, pointing out the effects of the electric field on the conductance [19]. Also, the electrical transport properties in graphene superlattices modulated by a homogeneous electric field have been studied [20].…”

“…It is very important to mention that in [20] the current density for a graphene (symmetric) superlattice is computed and comparisons between the monolayer and bilayer graphene structures are performed. Our results are different from [20] because we are focused on the asymmetric graphene structures and the interplay between the electric field and the asymmetry is pointed out.…”

Spin-polarized current produced by graphene superlattice

“…The transmission probability coefficient and the characteristics of the relationship between current density and voltage in a finite superlattice were firstly studied by Esaki and Tsu in 1973 [24]. Since the experimental realization of graphene superlattices [25][26][27], the transport properties in graphene superlattice were extensively investigated [28][29][30][31][32][33][34][35][36]. The transport properties in graphene-based superlattice structure were first studied by Bai and Zhang [28] the authors found that the conductivity of the graphene superlattice depends on the superlattice structural parameters.…”

“…[31], and the authors found that the conductance vanishes when the sample size becomes very large. Also, reference [32] studied current density in graphene superlattices without taking into account the spin states of the electron. The mentioned reference did not also consider external magnetic field and RSOI.…”