Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Researchers observe quantum interferences in real-time using a new extreme ultra-violet light spectroscopy technique

14.02.2020

A team headed by Prof. Dr. Frank Stienkemeier and Dr. Lukas Bruder from the Institute of Physics at the University of Freiburg has succeeded in observing in real-time ultrafast quantum interferences — in other words the oscillation patterns — of electrons which are found in the atomic shells of rare gas atoms. They managed to observe oscillations with a period of about 150 attoseconds — an attosecond is a billionth of a billionth of a second.

To this end, the scientists excited rare gas atoms with specially prepared laser pulses. Then they tracked the response of the atoms with a new measurement technique that enabled them to study quantum mechanical effects in atoms and molecules at extremely high time resolution. The researchers present their results in the latest edition of Nature Communications.


Laser pulses generate and track electronic quantum interference in an atom.

Graphic: AG Stienkemeier

Numerous chemical reactions, such as the breaking of bonds in molecules, are triggered by the absorption of light. In the first instant after the absorption, the distribution of the electrons in the atomic shell changes, significantly influencing the subsequent course of the reaction.

This alteration happens extremely quickly; the timescales reach into the attosecond range. Previously-used spectroscopic technologies, which use visible laser pulses, are not fast enough to track such processes.

So researchers around the world are currently developing innovative laser sources and adequate spectroscopic technologies in the ultra-violet and X-ray ranges.

Stienkemeier’s team has extended a technology known from the visible spectrum range, coherent pump-probe spectroscopy, into the ultra-violet range. This is the spectral range between X-ray radiation and ultra-violet light.

To do this, the scientists prepared a sequence of two ultra-short laser pulses in the extreme ultra-violet range at the FERMI free electron laser in Trieste, Italy. The pulses were separated by a precisely-defined time interval and had a precisely-defined phase relationship to one another.

The first pulse starts the process in the electron shell (pump-process). The second pulse probes the status of the electron shell at a later point (probe-process). By altering the time interval and the phase relationship, the researchers could reach conclusions on the temporal development in the electron shell.

“The greatest challenge was to achieve precise control over the pulse properties and to isolate the weak signals,” explains Andreas Wituschek, who was in charge of the experimental procedure.

The Freiburg physicists studied the rare gas argon, amongst others. In argon the pump-pulse causes a special configuration of two electrons within the atomic shell: this configuration disintegrates, with one electron leaving the atom in a very short time and the atom finally remaining behind as an ion.

The researchers succeeded for the first time in observing the immediate temporal decay of the quantum interference, as one electron left the atom.

“This experiment paves the way for many new applications in the study of atomic and molecular processes after selective stimulation with high-energy radiation in the extreme ultra-violet range,” says Bruder.

The research project was funded within the framework of the International Graduate School CoCo, which was established by the German Research Foundation (DFG), as well as by the COCONIS project of the European Research Council (ERC) and LoKoFEL project of the Federal Ministry of Education and Research (BMBF).

Original publication:
Wituschek A., Bruder L., Allaria E., Bangert U., Binz M., Borghes R., Callegari C., Cerullo G., Cinquegrana P., Giannessi L., Danailov M., Demidovich A., Di Fraia M., Drabbels M., Feifel R., Laarmann T., Michiels R., Mirian N.S., Mudrich M., Nikolov I., O’Shea FH., Penco G., Piseri P., Plekan O., Prince K.C., Przystawik A., Ribič P.R., Sansone G., Sigalotti P., Spampinati S., Spezzani C., Squibb R.J., Stranges S., Uhl D. & Stienkemeier F. (2020):Tracking attosecond electronic coherences using phase-manipulated extreme ultraviolet pulses. In: Nature Communications 11, 883 (2020). DOI: 10.1038/s41467-020-14721-2

Contact:
Prof. Dr. Frank Stienkemeier
Institute of Physics
University of Freiburg
Tel.: +49 761 203-7609
e-mail: stienkemeier@uni-freiburg.de

Originalpublikation:

https://www.pr.uni-freiburg.de/pm-en/press-releases-2020/electrons-in-rapid-moti...

Nicolas Scherger | idw - Informationsdienst Wissenschaft

More articles from Physics and Astronomy:

nachricht Scientists see energy gap modulations in a cuprate superconductor
02.04.2020 | DOE/Brookhaven National Laboratory

nachricht BESSY II: Ultra-fast switching of helicity of circularly polarized light pulses
02.04.2020 | Helmholtz-Zentrum Berlin für Materialien und Energie

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: Harnessing the rain for hydrovoltaics

Drops of water falling on or sliding over surfaces may leave behind traces of electrical charge, causing the drops to charge themselves. Scientists at the Max Planck Institute for Polymer Research (MPI-P) in Mainz have now begun a detailed investigation into this phenomenon that accompanies us in every-day life. They developed a method to quantify the charge generation and additionally created a theoretical model to aid understanding. According to the scientists, the observed effect could be a source of generated power and an important building block for understanding frictional electricity.

Water drops sliding over non-conducting surfaces can be found everywhere in our lives: From the dripping of a coffee machine, to a rinse in the shower, to an...

Im Focus: A sensational discovery: Traces of rainforests in West Antarctica

90 million-year-old forest soil provides unexpected evidence for exceptionally warm climate near the South Pole in the Cretaceous

An international team of researchers led by geoscientists from the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI) have now...

Im Focus: Blocking the Iron Transport Could Stop Tuberculosis

The bacteria that cause tuberculosis need iron to survive. Researchers at the University of Zurich have now solved the first detailed structure of the transport protein responsible for the iron supply. When the iron transport into the bacteria is inhibited, the pathogen can no longer grow. This opens novel ways to develop targeted tuberculosis drugs.

One of the most devastating pathogens that lives inside human cells is Mycobacterium tuberculosis, the bacillus that causes tuberculosis. According to the...

Im Focus: Physicist from Hannover Develops New Photon Source for Tap-proof Communication

An international team with the participation of Prof. Dr. Michael Kues from the Cluster of Excellence PhoenixD at Leibniz University Hannover has developed a new method for generating quantum-entangled photons in a spectral range of light that was previously inaccessible. The discovery can make the encryption of satellite-based communications much more secure in the future.

A 15-member research team from the UK, Germany and Japan has developed a new method for generating and detecting quantum-entangled photons at a wavelength of...

Im Focus: Junior scientists at the University of Rostock invent a funnel for light

Together with their colleagues from the University of Würzburg, physicists from the group of Professor Alexander Szameit at the University of Rostock have devised a “funnel” for photons. Their discovery was recently published in the renowned journal Science and holds great promise for novel ultra-sensitive detectors as well as innovative applications in telecommunications and information processing.

The quantum-optical properties of light and its interaction with matter has fascinated the Rostock professor Alexander Szameit since College.

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

13th AKL – International Laser Technology Congress: May 4–6, 2022 in Aachen – Laser Technology Live already this year!

02.04.2020 | Event News

“4th Hybrid Materials and Structures 2020” takes place over the internet

26.03.2020 | Event News

Most significant international Learning Analytics conference will take place – fully online

23.03.2020 | Event News

 
Latest News

Capturing 3D microstructures in real time

03.04.2020 | Materials Sciences

First SARS-CoV-2 genomes in Austria openly available

03.04.2020 | Life Sciences

Do urban fish exhibit impaired sleep? Light pollution suppresses melatonin production in European perch

03.04.2020 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>