SPEAKER PROFILE



Dr. Alessandro Colombo
Laboratory for Solid State Physics, Physics Department, ETH Zurich

Switzerland

The ultrafast dance of superheated plasmonic nanoparticles

Abstract

The study of strongly out-of-equilibrium matter provides unique opportunities to explore regions of the phase diagram otherwise difficult to access, potentially leading to new insights into physical processes with technological implications. Still, the elusive nature of such transient states, especially at the nanoscale, makes direct structural investigations extremely challenging due to the simultaneous requirements of high spatial and temporal resolution. In this talk we report on the dynamics of silver nanocubes, superheated via plasmonic excitation, probed via the Coherent Diffraction Imaging technique at the Swiss Free Electron Laser. We observe a diverse range of transient and metastable structures, with lifetimes ranging from a few to thousands of picoseconds. In combination with full-scale molecular dynamics simulations, the observations are a robust probe for the understanding of the energy transfer between electrons and phonons, and the relevant implications of the nanoparticles size and symmetries on the following dynamics.

Bio

After the PhD degree obtained at the University of Milan in 2018, I worked for a year at CINECA (Bologna, Italy) where I learned advanced techniques for the optimization and parallelization of scientific software. I came back to academic research in 2019, where I started a postdoc in the group Daniela Rupp at ETH Zurich. Since the PhD project, my research has been focusing on data analysis methods for diffraction experiments at X-ray Free Electron Lasers (XFELs), with a specific interest for the development of new and unconventional methodologies unlocked by advances in computational capabilities. Our research group under the lead of Prof. Rupp develops innovative experimental schemes to investigate structural properties and light-triggered ultrafast processes in isolated nanostructures with XFEL and High Harmonic Generation light sources.