Fig. 2
From: Nanoplasmonic electron acceleration by attosecond-controlled forward rescattering in silver clusters
Molecular dynamics simulation of the asymmetric electron emission. a Scatter plot of final kinetic energies and emission times (Efinal, ttrans) of electrons emitted in upward (red) and downward (blue) direction from the simulation run for φ = 0 in Fig. 1c. The envelopes of the laser field and the indicated polarization field components inside the cluster are shown as gray area and solid curves, respectively (only components along x-axis, right scale). The time axis is centered at the peak of the ω/2ω probe pulse. b Cycle-resolved analysis of the electron emission times and energies (symbols, left scale) in the resonance region. Solid curves show the corresponding evolutions of the laser field (green) and the polarization field (magenta) inside the cluster (right scale). Fast electrons (Efinal > 500 eV, marked with boxes) are selected for further analysis. c Evolution of the single-particle energy Esp during the final transit (black) resulting from averaging over the selected trajectories. Subtracting the direct laser absorption \({\rm{\Delta }}{E_{{\rm{sp}},{\rm{las}}}} = {q_i}{\int} {\kern 1pt} {{\bf{\dot r}}_i} \cdot {{{{\cal E}}}_{{\rm{las}}}}{\rm{d}}t\) (green) yields the plasmonic contribution (magenta). d Projected trajectories x i (t) of the selected electrons and spatiotemporal plasmonic gain map \(\frac{\partial }{{\partial t}}V\left( {x,t} \right)\) sampled on the polarization axis. Dark orange regions mark high-gain points and horizontal arrows indicate optimal gate times for forward rescattering in upward and downward direction, respectively. At the time of the resonance, the cluster has expanded to a radius R ≈ 13 nm
