Lattice-pseudospin and spin-valley polarizations in dual ferromagnetic-gated silicene junction

TL;DR

This paper investigates how dual ferromagnetic gates in silicene can control spin, valley, and lattice-pseudo spin currents, enabling switching between different polarization states for potential spin-valleytronic and pseudospintronic applications.

Contribution

It introduces a novel dual ferromagnetic-gated silicene junction model that allows precise control over spin, valley, and sub-lattice pseudo-spin polarizations, including pure sub-lattice polarization.

Findings

Parallel junctions enable perfect spin-valley current control.

Anti-parallel barriers destroy filtering effects and produce pure sub-lattice polarization.

Reversing exchange fields switches between spin and valley polarizations.

Abstract

We study spin-valley and lattice-pseudo spin currents in a dual ferromagnetic-gated silicene-based junction. Silicene has buckled atomic structure which allows us to take sublattice-dependent ferromagnetism into account in the investigation. One of the study results show that transmission at the junctions exhibits anisotropic property only in anti-parallel cases. Interestingly, the studied junctions can be switched from a pure spin-polarizer to a pure valley-polarizer by reversing directions of exchange fields in the parallel junctions. The perfect control of spin-valley currents can be done only in the parallel cases and its resolution can be enhanced by increasing gate potential between the ferromagnetic barriers. The asymmetric barriers of anti-parallel junction is found to destroy both spin and valley filtering effects and yield a novel result, pure sub-lattice pseudo-spin polarization. The current in the anti-parallel junctions can be controlled to flow solely in either A or B sub-lattice, saying that the controllable lattice current in silicene is created in double ferromagnetic-gated junction. Our work reveals the potential of dual ferromagnetic-gated silicene junction which may be possible for applications in spin-valleytronics and lattice-pseudospintronics.