Dynamics, effciency and energy distribution of nonlinear   plasmon-assisted generation of hot carriers
  We employ nonlinear autocorrelation measurements to investigate plasmon-assisted hot carrier dynamics generated in optical gold antennas. We demonstrate that surface plasmons enable a nonlinear formation of hot carriers, providing thus a unique lever to optimize the energy distribution and generation efficiency of the photo-excited charges. The temporal response of the carriers' relaxation can be controlled within a range extending from 500~fs to 2.5~ps. By conducting a quantitative analysis of the dynamics, we determine the nonlinear absorption cross-section of individual optical antennas. As such, this work provides strong insights on the understanding of plasmon-induced hot carrier generation, especially in the view of applications where the time response plays a preponderant role. 
O. Demichel, M. Petit, S. Viarbitskaya, R. Mejard, F. de Fornel, E.   Hertz, F. Billard, A. Bouhelier and B. Cluzel
physics.optics