Heterogeneous dynamics and superdiffusion in a 2D model system.

摘要: We studied the bidimensional confined model system provided by a Langmuir monolayer of gold nanoparticles (GNP) of 5nm diameter at the air water interface subject to dynamical arrest. By X-ray Photon Correlation Spectroscopy (XPCS) we demonstrate heterogeneous dynamics and 2D superdiffusive behaviour on the nanoscale, similar to what we observed for a Langmuir monolayer of photosensitive azopolymers [1]. In particular we focus here on the fourth order susceptibility chi4, which is, at the best of our knowledge, for the first time directly accessed experimentally by our XPCS experiment, and allows a direct comparison with theoretical predictions.