Featured Research

from universities, journals, and other organizations

Timely discovery: Physics research sheds new light on quantum dynamics

Date:
May 15, 2012
Source:
Kansas State University
Summary:
Physicists have made a breakthrough that improves understanding of matter-light interactions. Their research allows double ionization events to be observed at the time scale of attoseconds and shows that these ionization events occur earlier than thought -- a key factor to improve knowledge of correlated electron dynamics.

Artist's view of non-sequential double ionization. The 3D plots on the circle were obtained from experimental data and show how the velocities of the two electrons change with the electric-field evolution of the ionizing pulse. The plot in the center is the sum of all these single measurements. From these data, the scientists can reconstruct the detailed process of the double ionization.
Credit: Christian Hackenberger, Max-Planck-Institute for Quantum Optics

Kansas State University physicists and an international team of collaborators have made a breakthrough that improves understanding of matter-light interactions.

Their research allows double ionization events to be observed at the time scale of attoseconds, which are one-billionth of a billionth of a second. The physicists have also shown that these ionization events occur earlier than thought -- a key factor to improving knowledge of correlated electron dynamics, which involve two electrons and their interactions with each other. The work appears in a recent issue of Nature Communications.

"The research involves studying if these correlated electrons, ejected from an atom or a molecule, are traveling in the same or opposite directions," said Nora Johnson, a doctoral student in physics from Dell Rapids, S.D. "We can also determine if one electron has all the energy or if they share energy equally."

Other university researchers involved include Itzik Ben-Itzhak, university distinguished professor of physics, and Matthias Kling, assistant professor of physics. Kling is the principal investigator for the project and is on research leave at the Max Planck Institute of Quantum Optics in Garching, Germany, where he is performing related research. All of the researchers are involved with the university's James R. Macdonald Laboratory.

Double ionization occurs when two electrons are removed from an atom -- a process that can be caused by an intense laser pulse. When double ionization occurs in the laser field it can take the form of a sequential process, in which the laser removes one electron and then removes the other electron. This project focuses on another mechanism -- the nonsequential process for ionization -- in which the laser removes one electron, which is accelerated and hits a second electron to excite it. The laser then knocks out the second electron from the atom.

The researchers sent a four femtosecond-long laser pulse onto argon atoms. A femtosecond is a millionth of a billionth of a second. While most of the argon atoms were singly ionized, approximately every thousandth atom underwent nonsequential double ionization.

"The surprising result is that everybody expected that the second electron becomes excited and then, when the laser field is the strongest, this electron is removed," said Ben-Itzhak, director of the Macdonald laboratory. "But it actually happens earlier."

The researchers discovered that the time between the recollision and the second ionization is about 400 attoseconds. This is about 200 attoseconds earlier than the peak of the field, which is when physicists expected the second ionization to occur.

Johnson conducted her early experiments at the Macdonald Laboratory. She performed more extensive experiments during a 2009 Fulbright Fellowship at the Max Planck Institute of Quantum Optics. The two organizations have an ongoing collaboration and the Kansas State University team is directly funded by a $400,000 National Science Foundation grant.

"The key is that Nora has brought knowledge from Germany about short pulses and we can now continue these experiments in Kansas," Ben-Itzhak said. "We have an ongoing collaboration with them that goes both ways."

Now that the researchers have made an important discovery with atoms, Johnson is performing a similar experiment with molecules. She is performing experiments at the Macdonald Laboratory and will use the laboratory's expertise in imaging molecules.

"A molecule is more complex than an atom, which typically means its reaction dynamics are richer," Johnson said. "We are excited to pursue correlated electron dynamics at the next level of complexity to further understand them."


Story Source:

The above story is based on materials provided by Kansas State University. Note: Materials may be edited for content and length.


Journal Reference:

  1. Boris Bergues, Matthias Kübel, Nora G. Johnson, Bettina Fischer, Nicolas Camus, Kelsie J. Betsch, Oliver Herrwerth, Arne Senftleben, A. Max Sayler, Tim Rathje, Thomas Pfeifer, Itzik Ben-Itzhak, Robert R. Jones, Gerhard G. Paulus, Ferenc Krausz, Robert Moshammer, Joachim Ullrich, Matthias F. Kling. Attosecond tracing of correlated electron-emission in non-sequential double ionization. Nature Communications, 2012; 3: 813 DOI: 10.1038/ncomms1807

Cite This Page:

Kansas State University. "Timely discovery: Physics research sheds new light on quantum dynamics." ScienceDaily. ScienceDaily, 15 May 2012. <www.sciencedaily.com/releases/2012/05/120515131721.htm>.
Kansas State University. (2012, May 15). Timely discovery: Physics research sheds new light on quantum dynamics. ScienceDaily. Retrieved July 31, 2014 from www.sciencedaily.com/releases/2012/05/120515131721.htm
Kansas State University. "Timely discovery: Physics research sheds new light on quantum dynamics." ScienceDaily. www.sciencedaily.com/releases/2012/05/120515131721.htm (accessed July 31, 2014).

Share This




More Matter & Energy News

Thursday, July 31, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Britain Testing Driverless Cars on Roadways

Britain Testing Driverless Cars on Roadways

AP (July 30, 2014) — British officials said on Wednesday that driverless cars will be tested on roads in as many as three cities in a trial program set to begin in January. Officials said the tests will last up to three years. (July 30) Video provided by AP
Powered by NewsLook.com
7 Ways to Use Toothpaste: Howdini Hacks

7 Ways to Use Toothpaste: Howdini Hacks

Howdini (July 30, 2014) — Fresh breath and clean teeth are great, but have you ever thought, "my toothpaste could be doing more". Well, it can! Lots of things! Howdini has 7 new uses for this household staple. Video provided by Howdini
Powered by NewsLook.com
Amid Drought, UCLA Sees Only Water

Amid Drought, UCLA Sees Only Water

AP (July 30, 2014) — A ruptured 93-year-old water main left the UCLA campus awash in 8 million gallons of water in the middle of California's worst drought in decades. (July 30) Video provided by AP
Powered by NewsLook.com
Smartphone Powered Paper Plane Debuts at Airshow

Smartphone Powered Paper Plane Debuts at Airshow

AP (July 30, 2014) — Smartphone powered paper airplane that was popular on crowdfunding website KickStarter makes its debut at Wisconsin airshow (July 30) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:

More Coverage


Billiard Game in an Atom: Physicists Trace Double Ionization of Argon Atoms on Attosecond Time Scales

May 8, 2012 — Physicists have traced the double ionization of argon atoms on attosecond time scales. When an intense laser pulse interacts with an atom it generates agitation on the micro scale. The most likely ... read more
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



    Save/Print:
    Share:  

    Free Subscriptions


    Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

    Get Social & Mobile


    Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

    Have Feedback?


    Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
    Mobile iPhone Android Web
    Follow Facebook Twitter Google+
    Subscribe RSS Feeds Email Newsletters
    Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins