Electromodulation of the magnetoresistance and spin-valley polarization in Fibonacci silicene superlattices by external electric fields

The transmittance, spin-valley polarization, and tunnelling magnetoresistance of ferromagnetic silicene superlattice following Fibonacci sequence are explored via the transfer matrix method and Landauer–Büttiker theory. These physical quantities were studied for the lowest three Fibonacci orders ( S 2 , S 4 , a n d S 6 ) by varying an external electric field applied perpendicularly on the silicene layer and by adjusting the incident energy of Dirac electrons. Two cases of magnetization were addressed: parallel and antiparallel magnetizations. Our finding reveals that in the S 2 order, the equivalence between the conductances of electrons in K valley and electrons with opposite spin in K ′ valley leads to zero polarizations in AM magnetization. However, the high order sequences ( S 4 , a n d S 6 ) present an aperiodic distribution of wells and barriers leading to non-zero polarizations. Additionally, we find that increasing the electric field intensity diminishes the conductance for all sequence orders, however, augmenting the incident energy enlarges the conductance and introduces a splitting of some conductance components. The dependence of tunneling magnetoresistance on electric field and incident electron energy is also discussed and commented for different sequences. A stable and perfect TMR percentage is obtained for the S 6 sequence at lower incident energies.