Physicists observe electron ejected from atom for first time

Physicists at the University of California, Berkeley in collaboration with researchers from the Max Planck Institute of Quantum Optics and the U.S. Department of Energy's Lawrence Berkeley National Laboratory, became the first researchers to observe the motion of an atom's valence or outermost electrons in real-time by investigating the ejection of an electron from an atom by an intense laser pulse.

In the experiments, an electron in a krypton atom is removed by a laser pulse that lasts less than four femtoseconds (one femtosecond is one millionth of one billionth of a second). This process leaves behind an atom with a pulsating positively charged hole in the valence shell, which originates from electronic wave functions of the atom.

The scientists led by Dr. Steve Leone, an ultrafast laser expert and the recent recipient of a National Security Science and Engineering Faculty Fellowship, used an extreme ultraviolet , the duration for which was 150 attoseconds (one attosecond is one billionth of one billionth of a second), to capture and photograph the movement of valence for the first time.

This research into electron motions is expected to enable the scientists to better control processes and materials that will improve high-speed electronics and carbon-free energy sources that will benefit both the Air Force and consumers.

"If we want to understand high speed electronics, we need to work on changing molecular bonds in chemical reactions and the movement of electrons during chemical reactions or in complex solids which will only be possible by freezing time in a femtosecond," said Leone.

Dr. Michael R. Berman, program manager at AFOSR who is overseeing the scientists believes their research is an elegant example of the new capabilities of pulses to probe the dynamics of electron motions.

"This program and instrumentation will open new doors into probing fundamental physical processes on time scales faster than ever probed before."

Berman also noted, "These new tools will let us probe electron dynamics in materials and semiconductors and could help us understand and reduce electron loss processes to make electronics and devices like solar cells more efficient and to bring electronic data processing to its highest level."

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For the First Time Ever, Scientists Watch an Atom's Electrons Moving in Real Time

Provided by Air Force Office of Scientific Research
Citation: Physicists observe electron ejected from atom for first time (2010, October 12) retrieved 23 September 2019 from
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User comments

Oct 12, 2010
No Pix, No Clix...just kidding!

Oct 12, 2010
Where's the paper on this? Surely this is a poor reporting of the facts. Imagine the implications - what of the uncertainty principle?

Oct 12, 2010
ImAsht: As long as the product of the uncertainty in momentum and position are greater than or equal to h/4π, the uncertainty principle's alive and well. That's a ridiculously small value, and even supposing they got values for both position and momentum, they probably didn't even work things down to a squeezed state (that is, where the product of the two uncertainties equals h/4π; the lowest you can go).

Still, very interesting, this--although rather less clear than one might wish. How did they measure this, I wonder? Repeatedly smacking the ion with light of the right wavelength to be reflected and not absorbed (I don't really understand how reflection works, so...myeah. That last sentence may be colossally ignorant; sorry, if that's the case), and looking at the different angles of deflection?

Oct 13, 2010
Why the link to the original article isn't included - isn't Nature a reliable source enough?


Oct 13, 2010
Do we know enough to determine if the observed, free electron was actually a prior constituent of the atom or if it was spontaneously generated in reaction to the energetic pulse?

Oct 13, 2010
Zenmaster: I gather (I may be wrong; as noted, the article is a little confusing) that it isn't the ejected electron being observed, but the hole left behind after it was ejected.

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