Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Freiburg researchers investigate ultrafast reaction of superfluid helium triggerd by extreme ultraviolet laser pulses

08.01.2020

A team headed by Professor Frank Stienkemeier at Freiburg’s Institute of Physics and Dr. Marcel Mudrich, professor at the University of Aarhus in Denmark, has observed the ultrafast reaction of nanodroplets of helium after excitation with extreme ultraviolet radiation (XUV) using a free-electron laser in real time. The researchers have published their findings in the latest issue of Nature Communications.

Lasers generating high-intensity and ultra-short XUV and X-ray pulses give researchers new options for investigating the fundamental properties of matter in great detail. In many such experiments, material samples in the nanometer range are of particular interest.


Excitation of helium nanodroplets by ultra-short laser pulses.

Photo: AG Stienkemeier

Some scientists use helium droplets no larger than a few nanometers as a means of transporting and studying embedded molecules and molecular nanostructures. Helium droplets are ideally suited for this purpose because they possess extraordinary properties.

At an extremely low temperature of only 0.37 degrees above absolute zero, they move frictionlessly and are thus considered superfluids. Moreover, helium droplets usually are inert to the embedded molecules’ chemical processes and are completely transparent to infrared and visible light.

The team led by Stienkemeier and Mudrich wanted to find out how one of these superfluid droplets itself reacts when hit directly by an intense XUV laser pulse. The researchers used the world's first and only seeded free-electron laser FERMI in Trieste, Italy, which delivers high-intensity XUV pulses at a wavelength set by the team.

Supported by model calculations, the researchers identified three elementary reaction steps: A very fast localization of electrons, the population of metastable states, and the formation of a bubble that eventually bursts at the surface of the droplets and ejects a single excited helium atom.

“For the first time, we have managed to directly follow these processes in superfluid helium, which take place in an extremely short time,” says Mudrich.

“The results help to understand how nanoparticles interact with energetic radiation and then decay,” Stienkemeier adds. “This is essential information for the work aiming at directly imaging individual nanoparticles," he explains, “as it is being carried out at new intense radiation sources such as the European X-ray laser XFEL in Hamburg.”

Publication:
Mudrich, M., LaForge, A., Ciavardini, A., O'Keeffe, P., Callegari, C., Coreno, M., Demidovich, A., Devetta, M., Di Fraia, M., Drabbels, M., Finetti, P., Gessner, O., Grazioli, C., Hernando, A., Neumark, D., Ovcharenko, Y., Piseri, P., Plekan, O., Prince, K., Richter, R., Ziemkiewicz, M., Möller, T., Eloranta, J., Pi, M., Barranco, M., Stienkemeier, F. (2020): „Ultrafast relaxation of photoexcited superfluid He nanodroplets“ In: Nature Communications 11. DOI: 10.1038/s41467-019-13681-6

Contact:
Prof. Dr. Frank Stienkemeier
Institute of Physics
University of Freiburg
Phone: 0761/203-7609
E-Mail: stienkemeier@uni-freiburg.de

Originalpublikation:

https://www.nature.com/articles/s41467-019-13681-6

Nicolas Scherger | Albert-Ludwigs-Universität Freiburg im Breisgau
Further information:
http://www.uni-freiburg.de/

More articles from Physics and Astronomy:

nachricht Time-resolved measurement in a memory device
19.02.2020 | ETH Zurich

nachricht Studying electrons, bridging two realms of physics: connecting solids and soft matter
18.02.2020 | Tokyo University of Science

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: A step towards controlling spin-dependent petahertz electronics by material defects

The operational speed of semiconductors in various electronic and optoelectronic devices is limited to several gigahertz (a billion oscillations per second). This constrains the upper limit of the operational speed of computing. Now researchers from the Max Planck Institute for the Structure and Dynamics of Matter in Hamburg, Germany, and the Indian Institute of Technology in Bombay have explained how these processes can be sped up through the use of light waves and defected solid materials.

Light waves perform several hundred trillion oscillations per second. Hence, it is natural to envision employing light oscillations to drive the electronic...

Im Focus: Freiburg researcher investigate the origins of surface texture

Most natural and artificial surfaces are rough: metals and even glasses that appear smooth to the naked eye can look like jagged mountain ranges under the microscope. There is currently no uniform theory about the origin of this roughness despite it being observed on all scales, from the atomic to the tectonic. Scientists suspect that the rough surface is formed by irreversible plastic deformation that occurs in many processes of mechanical machining of components such as milling.

Prof. Dr. Lars Pastewka from the Simulation group at the Department of Microsystems Engineering at the University of Freiburg and his team have simulated such...

Im Focus: Skyrmions like it hot: Spin structures are controllable even at high temperatures

Investigation of the temperature dependence of the skyrmion Hall effect reveals further insights into possible new data storage devices

The joint research project of Johannes Gutenberg University Mainz (JGU) and the Massachusetts Institute of Technology (MIT) that had previously demonstrated...

Im Focus: Making the internet more energy efficient through systemic optimization

Researchers at Chalmers University of Technology, Sweden, recently completed a 5-year research project looking at how to make fibre optic communications systems more energy efficient. Among their proposals are smart, error-correcting data chip circuits, which they refined to be 10 times less energy consumptive. The project has yielded several scientific articles, in publications including Nature Communications.

Streaming films and music, scrolling through social media, and using cloud-based storage services are everyday activities now.

Im Focus: New synthesis methods enhance 3D chemical space for drug discovery

After helping develop a new approach for organic synthesis -- carbon-hydrogen functionalization -- scientists at Emory University are now showing how this approach may apply to drug discovery. Nature Catalysis published their most recent work -- a streamlined process for making a three-dimensional scaffold of keen interest to the pharmaceutical industry.

"Our tools open up whole new chemical space for potential drug targets," says Huw Davies, Emory professor of organic chemistry and senior author of the paper.

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

70th Lindau Nobel Laureate Meeting: Around 70 Laureates set to meet with young scientists from approx. 100 countries

12.02.2020 | Event News

11th Advanced Battery Power Conference, March 24-25, 2020 in Münster/Germany

16.01.2020 | Event News

Laser Colloquium Hydrogen LKH2: fast and reliable fuel cell manufacturing

15.01.2020 | Event News

 
Latest News

"Make two out of one" - Division of Artificial Cells

19.02.2020 | Life Sciences

High-Performance Computing Center of the University of Stuttgart Receives new Supercomuter "Hawk"

19.02.2020 | Information Technology

A step towards controlling spin-dependent petahertz electronics by material defects

19.02.2020 | Power and Electrical Engineering

VideoLinks
Science & Research
Overview of more VideoLinks >>>