  Magnetic silicene superlattices (MSSLs) are versatile structures with
spin-valley polarization and tunneling magnetoresistance (TMR) capabilities.
However, the oscillating transport properties related to the superlattice
periodicity impede stable spin-valley polarization states reachable by
reversing the magnetization direction. Here, we show that aperiodicity can be
used to improve the spin-valley polarization and TMR by reducing the
characteristic conductance oscillations of periodic MSSLs (P-MSSLs). Using the
Landauer-B\"uttiker formalism and the transfer matrix method, we investigate
the spin-valley polarization and the TMR of Fibonacci (F-) and Thue-Morse (TM-)
MSSLs as typical aperiodic superlattices. Our findings indicate that aperiodic
superlattices with higher disorder provide better spin-valley polarization and
TMR values. In particular, TM-MSSLs reduce considerably the conductance
oscillations giving rise to two well-defined spin-valley polarization states
and a better TMR than F- and P-MSSLs. F-MSSLs also improve the spin-valley
polarization and TMR, however they depend strongly on the parity of the
superlattice generation.
