Research articlesValley polarized current and Fano factor in a ferromagnetic/normal/ferromagnetic silicene superlattice junction

In this paper, based on the transfer-matrix method, we investigate the transport properties of Dirac fermions through a superlattice of ferromagnetic/normal/ferromagnetic (FNF) buckled silicene junction where an electrostatic gate potential U is attached to the normal region. It is found that owing to buckled structure of silicene, the transmission probabilities and consequently valley-resolved conductance of the junction can be turned on or off by adjusting electric field strength, the number of barriers, and electrostatic gate voltage. Remarkably, the fully valley polarized current can be achieved by increasing the number of barriers in the proposed device. The effect of the number of barriers on the total charge conductance Gc of such a junction versus barrier length has also been investigated and it is shown that by increasing the number of barriers the amplitudes of Gc oscillations decrease. It is also found that Fano factor strongly modulated by applying electric field, number of barriers, and gate voltage. In particular, in presence of an electrostatic gate potential, Fano factor reaches the full Poissonian value F=1, which signifies that transport is forbidden (T→0) and pure tunneling occurs in this junction.