The new technology allows tracking extremely fast processes in miniature objects – with an unparalleled spatial and temporal resolution. "For the first time we were able to determine the duration of electron oscillations in a single nano structure", says Professor Tobias Brixner of the Institute for Physical and Theoretical Chemistry of the University of Würzburg.
Ultra-short laser pulses (red) are used to measure electron oscillations (red balls) at the surface of a nano-structure. Image: Walter Pfeiffer, Bielefeld University
The analyses have shown that the collective electron movement after exciting a silver nano structure with light lasts up to 20 times longer in certain places than was thought. The duration of electron oscillations is of interest not only for basic research. It also has a significant influence on the efficiency of energy transport processes as occur, for instance, in photovoltaic cells or during the photosynthesis of plants.
"Our new method will allow us in the future to track very fast processes in many natural and artificial nano-structured materials", the scientists explain.
The research team and its sponsors
The teams of Professor Martin Aeschlimann (Kaiserslautern), Tobias Brixner (Würzburg) and Walter Pfeiffer (Bielefeld) presented their new analysis method on 11 August 2011 in the internationally renowned "Science" magazine that can be read online at http://www.sciencexpress.org. The German research association (DFG) has supported the project of the three research teams within the scope of its priority program "Ultrafast Nano-Optics".
Electron microscopy combined with laser flashes
How did the cooperation partners accomplish this success? They combined the advantages of an electron microscope with the excitation of ultra-short laser flashes and the high time resolution that can be achieved by this. This enables them to detect structures ten times smaller than would be possible using optical microscopes. The progress of the object properties can thus be followed with the extremely high time resolution of a few femtoseconds – an inconceivably short period of time during which a jet plane travels a distance smaller than the diameter of an atom", as Professor Brixner compares.
In order to be able to track ultrafast processes in the microcosm, the researchers use a complex sequence of ultra-short laser pulses which experts refer to as "coherent two-dimensional nanoscopy". The physicists and physical chemists finally accomplished their goal by developing a new sequence of laser pulses and the proof of the electrons emitted in this process.
„Coherent Two-Dimensional Nanoscopy“, Martin Aeschlimann, Tobias Brixner, Alexander Fischer, Christian Kramer, Pascal Melchior, Walter Pfeiffer, Christian Schneider, Christian Strüber, Philip Tuchscherer, Dmitri V. Voronine, Science, August 11, 2011, DOI 10.1126/science.1209206
Prof. Dr. Tobias Brixner, University of Würzburg, T +49 (0)931 31-86330, firstname.lastname@example.org
Prof. Dr. Martin Aeschlimann, University of Kaiserslautern, T +49 (0)631 205-2322, email@example.com
Prof. Dr. Walter Pfeiffer, University of Bielefeld, T +49 (0)521 106-6908, firstname.lastname@example.org
Study offers new theoretical approach to describing non-equilibrium phase transitions
27.04.2017 | DOE/Argonne National Laboratory
SwRI-led team discovers lull in Mars' giant impact history
26.04.2017 | Southwest Research Institute
More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.
Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...
Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.
"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...
The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.
Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...
The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...
Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.
Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...
20.04.2017 | Event News
18.04.2017 | Event News
03.04.2017 | Event News
27.04.2017 | Life Sciences
27.04.2017 | Physics and Astronomy
27.04.2017 | Earth Sciences