With the development of nanotechnology,many new optical phenomena in nanoscale have been demonstrated.Through the coupling of optical waves and collective oscillations of free electrons in metallic nanostructures,surface plasmon polaritons can be excited accompanying a strong near field enhancement that decays in a subwavelength scale,which have potential applications in the surface-enhanced Raman scattering,biosensor,optical communication,solar cells,and nonlinear optical frequency mixing.In the present article,we review the Green's matrix method for solving the surface plasmon resonances and near field in arbitrarily shaped nanostructures and in binary metallic nanostructures.Using this method,we design the plasmonic nanostructures whose resonances are tunable from the visible to near-infrared,study the interplay of plasmon resonances,and propose a new way to control plasmonic resonances in binary metallic nanostructures.
We demonstrate that the n-partite continuous-variable entanglement can be unconditionally prepared among n parties that share no common past, from n two-mode squeezed states. Both CHZ-like and cluster-like states can be generated for any nonzero squeezing in the entangled sources. An application of the resulting multipartite entangled state to a teleportation network is illustrated.
