Spin- and valley- dependent energy band and polarization in ferromagnetic silicene superlattice with circularly polarized light

We investigated the spin- and valley-dependent energy band and transport properties in ferromagnetic silicene superlattice with an off-resonant circularly polarized light. It is obviously found that the spin- and valley-dependent energy gap can be well tuned via the off-resonant circularly polarized light. Fully spin and valley-polarized can be realized in certain ranges of light intensity. What is particularly interesting is that by slightly adjusting the energy of the light field, the valley polarization can be suddenly reversed from 100% to -100%. Thus, our results are expected to be informative for switching devices related to valleytronics.

Automated summary

The study demonstrates that the spin- and valley-dependent energy gap in ferromagnetic silicene superlattice can be well tuned via off-resonant circularly polarized light, leading to fully spin and valley-polarization. Moreover, adjusting the energy of the light field can abruptly reverse valley polarization from 100% to -100%.