title: Negative electron energy loss and second-harmonic emission of nonlinear nanoparticles.
abstract: A fast and general technique to investigation the interaction between a fast electron and nonlinear materials consisting of centrosymmetric spheres is presented by means of multiple scattering of electromagnetic multipole fields. Two kinds of new effect, the negative electron energy loss caused by the second-harmonic field and the second-harmonic Smith-Purcell radiation using finite chain of nonlinear spheres, are predicted for the first time. It is shown that these new effects can be probed by the electron energy loss spectrum, suggesting their possible applications in tunable light sources for the second-harmonic generation.
authors: School of Physics, Beijing Institute of Technology, 100081 Beijing, China.
authors: Jinying
authors: J
authors: Xu
authors: Xiangdong
authors: X
authors: Zhang