The FERMI free electron laser: a breakthrough in ultrafast soft x-ray spectroscopies

Significant advances with extreme ultraviolet (EUV) and soft x-ray spectroscopies have been recently achieved at the FERMI free electron laser in Trieste (Italy). Time-resolved x-ray absorption spectroscopy (tr-XAS) has been used to explore the sub-picosecond structural and electronic rearrangement in materials under extreme conditions of pressure and temperature driven by intense fs-laser pulses [1]. tr-XAS has been found to be effective also for monitoring the ultrafast charge transfer in photo-excited functional materials containing metallic nanoparticles [2] as well as polaron formation in metal oxides. Moreover, tr-XAS has been successfully employed in combination with impulsive stimulated Raman scattering for analyzing the molecular motion in real time with unprecedented elemental and enantiomeric selectivity [3]. High sensitivity to nanometric buried interfaces between materials has been demonstrated by nonlinear second harmonic spectroscopy in the EUV range [4,5].

Finally, preliminary tr-XAS experiments have been attempted aimed at following laser driven ultrafast irreversible chemical reactions. This seminar provides an overview on these disruptive experiments carried out at the beamline TIMEX of FERMI, outlining next challenging developments, possible collaborations and new future opportunities for scientific research.

References 

Principi, , Krylow, S., Garcia, M.E., Simoncig, Physical Review Letters 125 ,155703 (2020)

Cresi, S.P., Principi, E., Spurio, E., Catone et al. Nano Letters 21, 1729 (2021)

Mincigrucci , Rouxel J. R., Rossi B., Principi E. et al. Nature Communications 14, 386 (2023)

Lam, K., Raj, S.L., Pascal, T.A., Pemmaraju, C.D. et al. Physical Review Letters 120, 023901 (2018)

Schwartz, P., Raj, S.L., Jamnuch, S., Hull, C.J., et al. Physical Review Letters 127, 096801 (2021)