Effects of a noncausal electromagnetic response on the linear momentum transfer from a swift electron to a metallic nanoparticle

Electron beams in Scanning Transmission Microscopes (STEMs) can be used as a tool to induce movement on nanoparticles. Employing classical-electrodynamics approach, it has been reported that the linear momentum transfer from STEM-beam electron metallic spherical nanoparticle either repulsive or attractive towards swift trajectory. This is qualitative agreement with experimental observations. The interaction time between and typically order of attoseconds. Hence, electromagnetic response at short times utmost importance. However, dielectric function employed previous studies presented non-causal pre-echo attosecond timescale, which might have lead incorrect unphysical results. Therefore, validity these results should revisited. In this theoretical work, we study non-causality effects transferred nanoparticle, made aluminum gold. Using an efficient numerical methodology, found non-causality, well deficient convergence, may Contrary what reported, our show gold nanoparticles, radius 1 nm, always attractive.