Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Jupiter’s „Trojans“ on an Atomic Scale

25.01.2012
The planet Jupiter keeps asteroids on stable orbits – and in a similar way, electrons can be stabilized in their orbit around the atomic nucleus. Calculations carried out at the Vienna University of Technology have now been verified in an experiment.

Planets can orbit a star for billions of years. Electrons circling the atomic nucleus are often visualized as tiny planets. But due to quantum effects, the behavior of atoms usually differs significantly from planetary systems. Austrian and US-American scientists have now succeeded in keeping electrons on planet-like orbits for a long time. This was done using an idea from astronomy: Jupiter stabilizes the orbits of asteroids (the so called “Trojans”), and in a very similar way, the orbits of electrons around the nucleus can be stabilized using an electromagnetic field. The results of this experiment have now been published in the journal “Physical Review Letters”.


Giant Atoms

They are probably the largest atoms on earth: “The diameter of the electronic orbits is several hundredths of a millimeter – an enormous distance on an atomic scale”, says Shuhei Yoshida (Vienna UT). The atoms are even larger than erythrocytes. Yoshida made the calculations at Vienna University of Technology, the experiment was carried out at Rice University in Houston (Texas).

The Electron is not a Planet

The idea that atoms are similar to planetary systems dates back to Niels Bohr: he came up with the first atomic model, in which electrons circle the nucleus in well-defined orbits. This view, however, is now seen to be outdated. In quantum physics, the electron is described as a quantum wave, or a “probability cloud”, that surrounds the atomic nucleus. The location of an electron in the ground state (the lowest possible energy level) is not well defined. Relative to the nucleus, it is situated in all possible directions at the same time. Asking about its “real position” or its orbit just does not make sense. Only if the electron is transferred into a state of higher energy, it can be manipulated in such a way that it moves along orbit-like paths.

Jupiter’s trick – Used for the Atom

Unlike planets, electrons will not keep moving in such an orbit for ever. “Without additional stabilization, the electron-wave would become delocalized after a few cycles”, says Professor Joachim Burgdörfer, head of the Institute for Theoretical Physics at Vienna UT. A simple idea on how to stabilize orbits has been known in astronomy for a long time: the gravity of Jupiter, the heaviest planet in our solar system, stabilizes the orbits of the “Trojans” – thousands of small asteroids. They aggregate around so-called “Lagrange points” on Jupiter’s orbital path. Staying close to these Lagrange points, the asteroids circle the sun together with the planet – with exactly the same orbital velocity, so that the asteroids never collide with Jupiter.

In the experiment, the stabilizing influence of Jupiter’s gravity is substituted by a cleverly designed electromagnetic field. The field oscillates precisely with the frequency corresponding to the orbital period of the electron around the nucleus. It sets the pace for the electron, and that way the electron-wave is kept at a specific point for a long time – much like a large number of asteroids, staying close to Jupiter’s Lagrange points on their orbit around the sun. Quantum physics even allows manipulations which are impossible in a planetary system: using the electromagnetic field, the electron can by shifted into a different orbit – as if the orbit of Jupiter and its asteroids was suddenly shifted to the orbit of Saturn.

Big and Small

The physicists succeeded in creating an atomic miniature version of a solar system and preparing atoms which are remarkably close to the historic Bohr model. In future, the researchers want to prepare atoms in which several electrons move on planetary orbits at the same time. Using such atoms, it should be possible to investigate in greater detail how the quantum-world of tiny objects corresponds to the classical world as we perceive it.

Picture download: http://www.tuwien.ac.at/dle/pr/aktuelles/downloads/2012/trojaner

Original publication: http://link.aps.org/doi/10.1103/PhysRevLett.108.043001

Further information:
Prof. Shuhei Yoshida
Institute for Theoretical Physics
Vienna University of Technology
Wiedner Hauptstraße 8, 1040 Wien
+43-1-58801-13611
shuhei.yoshida@tuwien.ac.at
Prof. Joachim Burgdörfer
Institute for Theoretical Physics
Vienna University of Technology
Wiedner Hauptstraße 8, 1040 Wien
+43-1-58801-13610
burg@concord.itp.tuwien.ac.at

Florian Aigner | EurekAlert!
Further information:
http://www.tuwien.ac.at
http://www.tuwien.ac.at/en/news/news_detail/article/7371/

More articles from Physics and Astronomy:

nachricht NASA detects solar flare pulses at Sun and Earth
17.11.2017 | NASA/Goddard Space Flight Center

nachricht Pluto's hydrocarbon haze keeps dwarf planet colder than expected
16.11.2017 | University of California - Santa Cruz

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 “cosmic snake” reveals the structure of remote galaxies

The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.

Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...

Im Focus: Visual intelligence is not the same as IQ

Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.

That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...

Im Focus: Novel Nano-CT device creates high-resolution 3D-X-rays of tiny velvet worm legs

Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.

During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....

Im Focus: Researchers Develop Data Bus for Quantum Computer

The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.

Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...

Im Focus: Wrinkles give heat a jolt in pillared graphene

Rice University researchers test 3-D carbon nanostructures' thermal transport abilities

Pillared graphene would transfer heat better if the theoretical material had a few asymmetric junctions that caused wrinkles, according to Rice University...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Ecology Across Borders: International conference brings together 1,500 ecologists

15.11.2017 | Event News

Road into laboratory: Users discuss biaxial fatigue-testing for car and truck wheel

15.11.2017 | Event News

#Berlin5GWeek: The right network for Industry 4.0

30.10.2017 | Event News

 
Latest News

NASA detects solar flare pulses at Sun and Earth

17.11.2017 | Physics and Astronomy

NIST scientists discover how to switch liver cancer cell growth from 2-D to 3-D structures

17.11.2017 | Health and Medicine

The importance of biodiversity in forests could increase due to climate change

17.11.2017 | Studies and Analyses

VideoLinks
B2B-VideoLinks
More VideoLinks >>>