Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Ultrafast snapshots of relaxing electrons in solids

15.09.2017

Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!

When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole behind. For a long time, scientists have suspected that the liberated electron and the positively charged hole form a new kind of quasiparticle — known as ‘core-exciton’.


Attosecond flashes of light and x-rays take snapshots of fleeting electrons in solids.

Graphic: MPQ, Attoelectronics Group

But so far, there has not yet been a real proof of its existence. Scientists have a wide range of tools to track excitons in semiconductors in real-time. Those are generated by ordinary light, and can be employed in various applications in optoelectronics and microelectronics. On the contrary, core-excitons are extremely short-lived, and up to now, no technique was available to track their motion and deduce their properties.

A team of scientists led by Dr. Eleftherios Goulielmakis, head of the research group “Attoelectronics” at the Max Planck Institute of Quantum Optics, have been able to capture the dynamics of core-excitons in solids in real-time. Using flashes of x-ray radiation lasting only few hundred attoseconds (1 attosecond = 0.000000000000000001 seconds) followed by optical light flashes of similar duration (a tool developed by the group last year) the scientists obtain an ultrafast camera which allowed them to take snapshots of the short-lived excitons in silicon dioxide for the first time. The work is published in this week’s issue of the Science magazine (DOI:10.1126/science.aan4737).

“Core-excitons live for a very short time because their interactions with other particles in the solid quickly stops their motion,” said Antoine Moulet, leading author in this work. “In quantum mechanics we say that the exciton loses its coherence,” he adds.

A key tool to track the dynamics of core-excitons has been the development of attosecond light flashes in the optical range. The work was published by the Attoelectronics group last year.

“In our experiment we use x-ray flashes to light up core-excitons in solids, whereas the optical attosecond pulses provide the possibility to resolve this motion in real-time,” says Julien Bertrand, a former researcher in the group of Goulielmakis, at present assistant professor at Laval University, Canada. “The combination of both allowed us to take snapshots of the motion of core-excitons which lived for approximately 750 attoseconds.”

But the study was not limited to capturing these fleeting motions inside solids. “We were able to acquire quantitative information about the properties of core-excitons such as their miniature dimension which were merely bigger than that of a single atom, or how easily they are polarized by visible light,” says Goulielmakis. “Our technique advances excitonics, i.e. the measurement, the control and the application of excitons in the x-ray regime. But at the same time, it is a general tool for studying ultrafast x-ray initiated processes in solids on their natural time scales. Such a capability has never before been possible in x-ray science.”

The team now envisages applications of their technique for studying ultrafast processes at interfaces of solids, and new routes to realize ultrafast switches for x-ray radiation based on optical light fields. “With x-ray free electron lasers rapidly proliferating around the world, the capability of controlling x-rays with visible light becomes increasingly important,” says Goulielmakis. [EG/OM]

Original publication:
A. Moulet, J.B. Bertrand, T. Klostermann, A. Guggenmos, N. Karpowicz & E. Goulielmakis
Soft x-ray excitonics
Science, 15 September 2017, DOI: 10.1126/science.aan4737

Contact:

Dr. Eleftherios Goulielmakis
ERC Research Group Attoelectronics
Max Planck Institute of Quantum Optics
Laboratory for Attosecond Physics
Hans-Kopfermann-Str. 1, 85748 Garching, Germany
Phone: +49 (0)89 / 32 905 - 632
E-mail: Eleftherios.Goulielmakis@mpq.mpg.de

Dr. Olivia Meyer-Streng
Press & Public Relations
Max Planck Institute of Quantum Optics, Garching, Germany
Phone: +49 (0)89 / 32 905 - 213
E-mail: olivia.meyer-streng@mpq.mpg.de

Weitere Informationen:

http://www.attoworld.de/goulielmakis-group

Dr. Olivia Meyer-Streng | Max-Planck-Institut für Quantenoptik
Further information:
http://www.mpq.mpg.de/

More articles from Physics and Astronomy:

nachricht New type of smart windows use liquid to switch from clear to reflective
14.12.2017 | The Optical Society

nachricht New ultra-thin diamond membrane is a radiobiologist's best friend
14.12.2017 | American Institute of Physics

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: Long-lived storage of a photonic qubit for worldwide teleportation

MPQ scientists achieve long storage times for photonic quantum bits which break the lower bound for direct teleportation in a global quantum network.

Concerning the development of quantum memories for the realization of global quantum networks, scientists of the Quantum Dynamics Division led by Professor...

Im Focus: Electromagnetic water cloak eliminates drag and wake

Detailed calculations show water cloaks are feasible with today's technology

Researchers have developed a water cloaking concept based on electromagnetic forces that could eliminate an object's wake, greatly reducing its drag while...

Im Focus: Scientists channel graphene to understand filtration and ion transport into cells

Tiny pores at a cell's entryway act as miniature bouncers, letting in some electrically charged atoms--ions--but blocking others. Operating as exquisitely sensitive filters, these "ion channels" play a critical role in biological functions such as muscle contraction and the firing of brain cells.

To rapidly transport the right ions through the cell membrane, the tiny channels rely on a complex interplay between the ions and surrounding molecules,...

Im Focus: Towards data storage at the single molecule level

The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.

Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...

Im Focus: Successful Mechanical Testing of Nanowires

With innovative experiments, researchers at the Helmholtz-Zentrums Geesthacht and the Technical University Hamburg unravel why tiny metallic structures are extremely strong

Light-weight and simultaneously strong – porous metallic nanomaterials promise interesting applications as, for instance, for future aeroplanes with enhanced...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

AKL’18: The opportunities and challenges of digitalization in the laser industry

07.12.2017 | Event News

 
Latest News

Plasmonic biosensors enable development of new easy-to-use health tests

14.12.2017 | Health and Medicine

New type of smart windows use liquid to switch from clear to reflective

14.12.2017 | Physics and Astronomy

BigH1 -- The key histone for male fertility

14.12.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>