Valley-spin transport and polarization in ferromagnetic silicene/germanene/ferromagnetic silicene junction

Two-dimensional materials such as silicene and germanene have attracted considerable attention due to their unique electronic and optoelectronic properties. When combined into heterostructures, these materials enable novel transport phenomena that are not accessible in isolated layers. In this work, we study the electronic transport properties of a silicene/germanene/silicene junction with ferromagnetic silicene leads. The transmission probability, conductance, and spin and valley polarization are analyzed using the transfer matrix method combined with the Landauer-Büttiker formalism. Our results demonstrate that both the on-site potential and the exchange energy in the silicene regions significantly and selectively modulate the conductance of the four transport channels (↑K,↓K,↑K',↓K'). By tuning these external parameters, fully spin- and valley-polarized transport regimes can be achieved. These findings provide valuable insights for the design of nanoscale devices and highlight the potential of silicene-germanene heterostructures for controllable spin-valleytronic applications.