Velocity modulation of electron transport through a ferromagnetic silicene junction

We address velocity-modulation control of electron wave propagation in a normal/ferromagnetic/normal silicene junc tion with local variation of Fermi velocity, where the properties of charge, valley, and spin transport through the junction ar investigated. By matching the wavefunctions at the normal-ferromagnetic interfaces, it is demonstrated that the variation of Fermi velocity in a small range can largely enhance the total conductance while keeping the current nearly fully valley and spin-polarized. Further, the variation of Fermi velocity in ferromagnetic silicene has significant influence on the valley and spin polarization, especially in the low-energy regime. It may drastically reduce the high polarizations, which can b realized by adjusting the local application of a gate voltage and exchange field on the junction.