Kiel nano-scientists take snapshots of electronic states
How fast an intense laser pulse can change the electrical properties of solids is revealed by researchers from Kiel University in the current edition of Nature (09.03.2011). Scientists in the team of Professor Michael Bauer, Dr. Kai Roßnagel and Professor Lutz Kipp from the Institute of Experimental and Applied Physics, together with colleagues from the University of Kaiserslautern and the University of Colorado in Boulder, U.S.A., are following the course of electronic switching processes which occur within fractions of a second (femtoseconds).
Laser system for generating ultra short x-ray pulses which is used in the experiment to make the recordings.
Photo: Rohwer et al., Copyright: CAU
The results of their research may trigger future developments of custom-made and ultra fast opto-electronic components in order to increase data transmission rates or to accelerate optical switches, to name just one example of potential areas of application.
"These techniques that we have developed enables us to record films of extremely fast processes in a much more comprehensive manner than it was previously possible with similar techniques", Bauer explains. "We are able to, for example, directly track phase transitions in solids or catalytic reactions on surfaces."
Two still frames recorded from the newly developed imaging method. The time interval between the two frames is only 0.00000000000007 seconds.
Recording: Rohwer et al., Copyright: CAU
To record the films, the Kiel scientists used ultra short flashes of light in the soft x-ray spectral region generated with a specific laser system. Bauer: "The amount of information gained from our pictures when played back in slow motion is vast. We will get completely new insights into most relevant electronic properties of solids which are important for a variety of current and future technologies, for example, in telecommunications."
The Christian-Albrechts-Universität zu Kiel (CAU) has proven international expertise as a North German research university in the field of nanosciences and surface science, for example, in the German Research Foundation’s Collaborative Research Centre 855 "Magnetoelectric Composites – Future Biomagnetic Interfaces". Furthermore, the CAU is applying for the current round of the Excellence Initiative with the excellence cluster "Materials for Life".
Background information:
Femto means "one part in a thousand million million". When, for example, molecules react with one another or when the switching states in electronic components change, processes at the atomic length scale are involved which take place on time scales of femtoseconds.
Ultra short laser pulses in the so-called "soft x-ray spectral region" – i.e. light with very short wavelengths – enables one to make snapshots of the electronic states which are transiently formed during a switching process, for example. The shots are combined in series to deliver a film depicting such switching processes with a level of detail and a temporal resolution which could previously not be achieved.
Video: Kiel University studies electric states in solids: A phase transition recorded in very slow motion in a solid, which is completed within an extremely short time.
Credit: Rohwer et al., CAU; Copyright: Nature
Source: Christian-Albrechts-Universitaet zu Kiel
Citation: Collapse of long-range charge order tracked by time-resolved photoemission at high momenta
Timm Rohwer, Stefan Hellmann, Martin Wiesenmayer, Christian Sohrt, Ankatrin Stange, Bartosz Slomski, Adra Carr, Yanwei Liu, Luis Miaja Avila, Matthias Kalläne, Stefan Mathias, Lutz Kipp, Kai Rossnagel & Michael Bauer
doi:10.1038/nature09829
http://www.nature.com/nature/journal/vaop/ncurrent/full/nature09829.html
How fast an intense laser pulse can change the electrical properties of solids is revealed by researchers from Kiel University in the current edition of Nature (09.03.2011). Scientists in the team of Professor Michael Bauer, Dr. Kai Roßnagel and Professor Lutz Kipp from the Institute of Experimental and Applied Physics, together with colleagues from the University of Kaiserslautern and the University of Colorado in Boulder, U.S.A., are following the course of electronic switching processes which occur within fractions of a second (femtoseconds).
Laser system for generating ultra short x-ray pulses which is used in the experiment to make the recordings.
Photo: Rohwer et al., Copyright: CAU
The results of their research may trigger future developments of custom-made and ultra fast opto-electronic components in order to increase data transmission rates or to accelerate optical switches, to name just one example of potential areas of application.
"These techniques that we have developed enables us to record films of extremely fast processes in a much more comprehensive manner than it was previously possible with similar techniques", Bauer explains. "We are able to, for example, directly track phase transitions in solids or catalytic reactions on surfaces."
Two still frames recorded from the newly developed imaging method. The time interval between the two frames is only 0.00000000000007 seconds.
Recording: Rohwer et al., Copyright: CAU
To record the films, the Kiel scientists used ultra short flashes of light in the soft x-ray spectral region generated with a specific laser system. Bauer: "The amount of information gained from our pictures when played back in slow motion is vast. We will get completely new insights into most relevant electronic properties of solids which are important for a variety of current and future technologies, for example, in telecommunications."
The Christian-Albrechts-Universität zu Kiel (CAU) has proven international expertise as a North German research university in the field of nanosciences and surface science, for example, in the German Research Foundation’s Collaborative Research Centre 855 "Magnetoelectric Composites – Future Biomagnetic Interfaces". Furthermore, the CAU is applying for the current round of the Excellence Initiative with the excellence cluster "Materials for Life".
Background information:
Femto means "one part in a thousand million million". When, for example, molecules react with one another or when the switching states in electronic components change, processes at the atomic length scale are involved which take place on time scales of femtoseconds.
Ultra short laser pulses in the so-called "soft x-ray spectral region" – i.e. light with very short wavelengths – enables one to make snapshots of the electronic states which are transiently formed during a switching process, for example. The shots are combined in series to deliver a film depicting such switching processes with a level of detail and a temporal resolution which could previously not be achieved.
Video: Kiel University studies electric states in solids: A phase transition recorded in very slow motion in a solid, which is completed within an extremely short time.
Source: Christian-Albrechts-Universitaet zu Kiel
Citation: Collapse of long-range charge order tracked by time-resolved photoemission at high momenta
Timm Rohwer, Stefan Hellmann, Martin Wiesenmayer, Christian Sohrt, Ankatrin Stange, Bartosz Slomski, Adra Carr, Yanwei Liu, Luis Miaja Avila, Matthias Kalläne, Stefan Mathias, Lutz Kipp, Kai Rossnagel & Michael Bauer
doi:10.1038/nature09829
http://www.nature.com/nature/journal/vaop/ncurrent/full/nature09829.html
Thanks for sharing those pictures..It was something new and interesting too..
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