A new challenge against time launched by FERMI laser light
To control ultrafast physical processes, which occur on a time scale of billionth of a billionth of a second, is now possible. This was done during a new, important experiment conducted by an international research team by using FERMI (Free Electron laser Radiation for Multidisciplinary Investigations): the fourth generation, free electron laser light source, located at the Elettra Sincrotrone research centre in Trieste.
By using a light beam produced by FERMI and consisting of two wavelengths – i.e. two different colours – the research team managed to control the direction of electrons emitted from a neon gas solicited by the radiation. In this way, scientists were able to follow the extremely fast “motion” of electrons with a resolution of attoseconds, on a time scale of billionth of a billionth of a second.
This result opens new prospects to the investigation of ultrafast phenomena: an investigation field where the first crucial results were obtained by Ahmed Zewail – who was awarded the Nobel Prize in Chemistry in 1999 – by using laser impulses of a few femtoseconds, equal to one millionth of one billionth of a second, the same time scale over which atoms form and break bonds. Nature however can be even faster. “Electrons are at the basis of chemical bonds, which in the processes they cause move a thousand times faster, that is attoseconds” – explained Kevin Prince, physicist at Elettra Sincrotrone Trieste and first author of the paper - “Like many in the scientific community, we have also been working for years to develop innovative analytical methods with attosecond resolution to study and control them. With this work, that exploits the exceptional properties of the laser light from FERMI, we can say we have finally achieved our goal.”
The study, published in the journal Nature Photonics, involved Italy to a great extent. The experiment involved scientists from several Italian research centres – besides Elettra Sincrotrone Trieste, Polytechnics University of Milan, the Institute of Photonics and Nanotechnologies (IFN), the Institute of Materials (IOM) and the Institute of Structure of Matter (ISM) of the National Research Council (CNR), and ENEA – together with researchers from Japan (Tohoku University), Russia (Moscow State University “Lomonosov”), United States (Drake University) and Germany (Polytechnic University of Berlin, University of Freiburgh, European XFEL, Max-Planck Institute for Nuclear Physics, Heidelberg).
“This result opens up new prospects for research on ultrafast processes and for attosecond physics in Italy, as well as at the international level” said Giuseppe Sansone who, with his group at the Polytechnic University of Milan, contributed to the planning and conduction of the experiment. “The next step” he added , “will be to apply the technique we have demonstrated to the study of more complex processes, such as catalytic processes and atmospheric chemistry.”