Analysis of Circularly Polarized Light Irradiation Effects on Double Ferromagnetic-Gate Silicene Junction

Abstract

We present an analytical study of effects that off-resonant circularly polarized light irradiation has on spin-valley currents in dual ferromagnetic-gate silicene-based junctions. Two identical electric fields are applied to both ferromagnetic (FM) gates. Two types of exchange field configurations, parallel (P) and anti-parallel (AP), are applied along with chemical potential to the FM gates in this investigation. The results show that application of circularly polarized light has an impact on polarized spin and valley current characteristics, particularly at the off-resonant frequency region. It also enhances the amplitude of tunnelling magnetoresistance (TMR) significantly. In addition, we found that exchange field configuration has an effect on both spin polarization and valley polarization. Our study reveals that light intensity plays the main role on the light irradiation effects, where the band structure and change electronic properties of the materials are modified by photon dressing to create a new phase of electronic structure. The change of band structure in each region affects the transmission coefficients and transmission probability amplitude of electrons, which in turn affects the conductance of each spin-valley current component. Our study suggests the potential of this scheme in applications, such as spin-valleytronic photo-sensing devices under polarized-photo irradiation.