A research team led by laser physicist Eleftherios Goulielmakis at Rostock University has developed a new technology, which makes it possible to image free electrons in crystalline materials.
Microscopes of visible light allow us to see tiny objects such living cells and their interior. Yet, they cannot discern how electrons are distributed among atoms in solids. Now researchers around Prof. Eleftherios Goulielmakis of the Extreme Photonics Labs at the University of Rostock and the Max Planck Institute of Quantum Optics in Garching, Germany, along with coworkers of the Institute of Physics of the Chinese Academy of Sciences in Beijing, developed a new type of a light microscope, the Picoscope, that allows overcoming this limitation. The researchers used powerful laser flashes to irradiate thin, films of crystalline materials. These laser pulses drove crystal electrons into a fast wiggling motion. As the electrons bounced off with the surrounding electrons, they emitted radiation in the extreme ultraviolet part of the spectrum. By analyzing the properties of this radiation, the researchers composed pictures that illustrate how the electron cloud is distributed among atoms in the crystal lattice of solids with a resolution of a few tens of picometers which is a billionth of a millimeter. The experiments pave the way towards developing a new class of laser-based microscopes that could allow physicists, chemists, and material scientists to peer into the details of the microcosm with unprecedented resolution and to deeply understand and eventually control the chemical and the electronic properties of materials. (Nature, July 1 2020)
PICTURE: © Universität Rostock/Christian Hackenberger