Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Quantum Mechanics not in Jeopardy - Physicists confirm a decades-old key principle experimentally

23.07.2010
When waves – regardless of whether light or sound – collide, they overlap creating interferences. Austrian and Canadian quantum physicists have now been able to rule out the existence of higher-order interferences experimentally and thereby confirmed an axiom in quantum physics: Born’s rule. They have published their findings in the scientific journal Science.

In quantum mechanics many propositions are made in probabilities. In 1926 German physicist Max Born postulated that the probability to find a quantum object at a certain place at a certain time equals the square of its wave function. A direct consequence of this rule is the interference pattern as shown in the double slit diffraction experiment.

Born’s rule is one of the key laws in quantum mechanics and it proposes that interference occurs in pairs of possibilities. Interferences of higher order are ruled out. There was no experimental verification of this proposition until now, when the research group led by Prof. Gregor Weihs from the University of Innsbruck and the University of Waterloo has confirmed the accuracy of Born’s law in a triple-slit experiment. “The existence of third-order interference terms would have tremendous theoretical repercussions – it would shake quantum mechanics to the core,“ says Weihs. The impetus for this experiment was the suggestion made by physicists to generalize either quantum mechanics or gravitation – the two pillars of modern physics – to achieve unification, thereby arriving at a one all-encompassing theory. “Our experiment thwarts these efforts once again,“ explains Gregor Weihs.

Triple-slit experiment
Gregor Weihs – Professor of Photonics at the University of Innsbruck – and his team are investigating new light sources to be used for transmitting quantum information. He developed a single-photon source, which served as the basis for testing Born’s rule. Photons were sent through a steel membrane mask which has three micrometer sized slits cut into it. Measurements were performed with the slits closed individually resulting in eight independent slit combinations. The data taken was then used to calculate whether Born’s rule applies. “In principle, this experiment is very simple,“ says Gregor Weihs “and we were quite surprised to find that nobody hadn’t performed this experiment before.” However, the physicists were struggling with measurement errors, which they were eventually able to overcome during their two year long Sisyphean task. “Our measurements show that we can rule out the existence of third-order interference up to a certain bound,“ says a happy experimental physicist Weihs. His next step will be to considerably lower the bound with an improved experiment.
Master of light particles
The experiment was performed at the Institute for Quantum Computing at the University of Waterloo in Canada, where Prof. Gregor Weihs worked before his appointment at the University of Innsbruck. Since 2008 he has been setting up his own research group at the Institute for Experimental Physics in Innsbruck, which now comprises twelve group members. The group, whose members come from all over the world, investigates the development of novel single-photon sources and entangled photon pairs from semiconductor nanostructures. The researcher’s ultimate goal is to integrate quantum optical experiments with functions on semiconductor chips.
Weitere Informationen:
http://www.uibk.ac.at/exphys/photonik/ - Research Group Photonics (G. Weihs)
http://www.uibk.ac.at - University of Innsbruck
http://www.iqc.ac.ca - Institute for Quantum Computing, University of Waterloo

Dr. Christian Flatz | idw
Further information:
http://www.uibk.ac.at

Further reports about: Pervasive Computing Photonic Quantum Waterloo light source quantum mechanics

More articles from Physics and Astronomy:

nachricht Further Improvement of Qubit Lifetime for Quantum Computers
09.12.2016 | Forschungszentrum Jülich

nachricht Electron highway inside crystal
09.12.2016 | Julius-Maximilians-Universität Würzburg

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: Electron highway inside crystal

Physicists of the University of Würzburg have made an astonishing discovery in a specific type of topological insulators. The effect is due to the structure of the materials used. The researchers have now published their work in the journal Science.

Topological insulators are currently the hot topic in physics according to the newspaper Neue Zürcher Zeitung. Only a few weeks ago, their importance was...

Im Focus: Significantly more productivity in USP lasers

In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.

Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

Researchers identify potentially druggable mutant p53 proteins that promote cancer growth

09.12.2016 | Life Sciences

Scientists produce a new roadmap for guiding development & conservation in the Amazon

09.12.2016 | Ecology, The Environment and Conservation

Satellites, airport visibility readings shed light on troops' exposure to air pollution

09.12.2016 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>