Silane Electron Energy Band And Transport Driven By Light Modulation And Periodic Potential

Based on the Floquet method,we study the photomodulated band structures and the electronic transport properties under the periodic driving potential in silicene theoretical-ly in this paper.Fistly,we study the band structures of the Floquet systems irradiated by variously polarized monochromatic light.It reveals that the circularly polarized light can generate the anisotropic chiral edge modes and the polarization of light further manipulates these modes by altering their spatial distributions and spin orientations.Benefitting from external electric and exchange fields,the valley polarizations and band gaps can be induced to implement a variety of exotic photo-dressed topological phases.We further investigate the effect of a time-dependent oscillating potential on the transport property of the elec-tron through a silicene electrostatic barrier.The corresponding transmission is studied as a function of the incident angle of the electron beam,the intensity of the exchange field and the potential parameters.Quantum interferences within the oscillating barrier have an important effect on quasiparticles tunneling.In particular,the time-periodic electrostat-ic potential generates additional sidebands at energies E0+nh?(n=0,± 1,...)in the transmission probability originating from the photon absorption or emission within the oscillating barrier,we truncate at n=±1 in the calculation of this paper.Finally we study the transport properties of the silicene nanoribbons subject to periodically driving electric and exchange fields.The multiple barriers made up of corresponding fields reshape the DC conductance by imposing pronounced both Fabry-Perot-and Fano-type resonances accompanied with high spin polarizations.In particular,a transport gap can be generated by the electric barriers with an appropriate strength,which is absent in the case of the barriers of the exchange field.The effects of the hybrid barriers including both electric and exchange fields,however,are not simply a mixture of two individual barriers,while depend on the relative phase of the time-varied barriers.In contrast to static barriers,the further studies of the driving frequency indicate that the in-gap states can survive in the transport gap for electric barriers as the frequency increases.This feature is particularly valuable for building spin-filter or spin-switcher devices.