The temporal dynamics of nonlocal plasmonic nanoparticle under the ultrashort pulses

Modern plasmonics plays a crucial role in photonics and optics, and paves a way for a variety of emerging applications. Since the stationary behavior of plasmonic nanoparticles is quite well studied, the quantum-driven ultrafast response of ultra-small particles in specific electromagnetic regimes attract ever-increasing attentions nowadays. In this paper, we investigate the temporal dynamics of the plasmonic nanoparticles involving nonlocal effect under the illumination by an external ultrashort pulse. We find that the intensity of the corresponding dipole moment can be globally suppressed and the magnitude of the time-shift decreases with the increase of nonlocality. In addition, we observe large decay rate and small oscillation period when the nonlocality is taken into account for quite small duration time near (or below) the surface plasmon resonant frequencies. Further discussion reveals that the time-shift can be either positive or negative because of the emergence of abnormal dispersion relationship. These reshaping on dipole moment in time domain may be applicable in the modulation on the ultrashort signals of nanophotonic devices.