Dynamical Polarization, Plasmon and Energy Loss of Kekule-distorted Graphene Under Circularly Polarized Irradiation

The high frequency electromagnetic irradiation within the off-resonance regime significantly changes the electronic transport and optical properties of Dirac systems. Here, we have studied the effect of circularly polarized irradiation on the energy band, dynamical polarization and the plasmon excitations of Kek-Y phases of graphene. It is found that the large gap is induced between two bands and between two concentric Dirac cones which considerably modifies the polarization function and consequently the plasmon dispersion. The plasmon damping rate and the rate of loss of energy of a charge particle moving parallel to the 2D sheet is calculated numerically. To further explore the electronic transport properties of Kek-Y graphene, the analytical solution for the transmission and reflection coefficients are also derived. It is observed that both the reflection and transmission of electrons conserve the energy, and therefore have the finite probability for the particle to transfer from one band to another.