Ultrafast induced electron-surface scattering in a confined metallic system

Ultrafast modifications of the electron scattering rate due to selective he ating of the free electron gas are investigated in silver nanoparticles emb edded in a glass matrix. Measurements were performed using a two-color femt osecond pump-probe technique and probing the induced changes of the surface plasmon resonance width. The results show that ultrafast heating of the el ectron gas leads to a large transient increase of the probability of electr on scattering off the nanoparticle surfaces, in agreement with a theoretica l model.