Surface molecular ionization imaging of gold nanocubes

The near-field enhancement effect in nanoparticles dominates the dynamical response of the atoms and molecules within the nanosystem when interacting with ultrashort laser pulses. In this work, using the single-shot velocity map imaging technique, the angle-resolved momentum distributions of the ionization products from surface molecules in gold nanocubes have been obtained. The far-field momentum distributions of the H⁺ ions can be linked with the near field profiles demonstrated by a classical simulation considering the initial ionization probability and the Coulomb interactions among the charged particles. This research provides an approach to look at the nanoscale near field distribution in the extreme interactions of femtosecond laser pulses and nanoparticles, paving the way for exploring the complex dynamics.