Unified hydrodynamic approach to laser field plasmon excitations in metal nanoparticles with general shape

摘要

We present a unified hydroelectrodynamical approach to study electron dynamics in a laser field in cold metal nanoparticles with a general nonspherical surface. This is the generalization to complex shapes of the model used earlier to study both linear and nonlinear plasmon excitations in thin metal films and spherical nanoparticles. Along with a general formulation allowing a direct nonlinear extension of the model for nanoparticles with nonspherical shapes, the linear plasmon excitations in metal cubic and rectangular parallelepiped nanoparticles are calculated as an example of using the hydrodynamic model in a cold charge-compensated electron plasma approximation. The results obtained for the cubic and parallelepipedlike nanoparticles are analyzed and compared with the ones of earlier approaches such as the discrete dipole approximation.