Nonlinear absorption and attenuation of electromagnetic plane wave in plasma are investigated.We employ a polarization theory of plane electromagnetic wave in plasma to obtain a nonlinear dynamic dielectric function.The wave vector is obtained considering linear and nonlinear effects.In a model with vertical incidence of plane electromagnetic wave into plasma slabs with metal underlay,the attenuation of electromagnetic wave and reflected power are deduced.It shows that the nonlinear effects should be considered.

The mesoscopic transport through a quantum dot and a toroidal carbon nanotube (TCN) coupled system is investigated with the nonequilibrium Green's function technique.The coherent tunneling is strongly related to the energy structures of the TCN and the quantum dot.The Aharonov-Bohm effect causes energy levels of the TCN to change periodically,and the tunneling current oscillates with the magnetic flux.The detailed nanostructure of TCN exhibits metal-semiconductor transition,and this behavior is reflected in the output current.The matching-mismatching of quantum levels of the sub-systems plays important role in the mesoscopic transport.

Quantum coherent transport through a superconductor-quantum-dot coupled system is investigated mainly for considering the current characteristics under the interactions of microwave field and Zeeman field. The mean field BCS theory and non-equilibrium Green function technique are employed to solve the tunneling problem. The Bogoliubov transformation is employed to derive the current formula, and the current-voltage, current-magnetic field and Josephson current curves are given by numerical calculations.