Featured Research

from universities, journals, and other organizations

Quantum mechanics not in jeopardy: Physicists confirm a decades-old key principle experimentally

Date:
July 23, 2010
Source:
University of Innsbruck
Summary:
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.

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.
Credit: Graphic by IQC

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.


Story Source:

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


Journal Reference:

  1. U. Sinha; C. Couteau; T. Jennewein; R. Laflamme; G. Weihs. Ruling out Multi-Order Interference in Quantum Mechanics. Science, 2010; DOI: 10.1126/science.1190545

Cite This Page:

University of Innsbruck. "Quantum mechanics not in jeopardy: Physicists confirm a decades-old key principle experimentally." ScienceDaily. ScienceDaily, 23 July 2010. <www.sciencedaily.com/releases/2010/07/100722142640.htm>.
University of Innsbruck. (2010, July 23). Quantum mechanics not in jeopardy: Physicists confirm a decades-old key principle experimentally. ScienceDaily. Retrieved September 18, 2014 from www.sciencedaily.com/releases/2010/07/100722142640.htm
University of Innsbruck. "Quantum mechanics not in jeopardy: Physicists confirm a decades-old key principle experimentally." ScienceDaily. www.sciencedaily.com/releases/2010/07/100722142640.htm (accessed September 18, 2014).

Share This



More Matter & Energy News

Thursday, September 18, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Virtual Reality Headsets Unveiled at Tokyo Game Show

Virtual Reality Headsets Unveiled at Tokyo Game Show

AFP (Sep. 18, 2014) — Several companies unveiled virtual reality headsets at the Tokyo Game Show, Asia's largest digital entertainment exhibition. Duration: 00:48 Video provided by AFP
Powered by NewsLook.com
Stocks Hit All-Time High as Fed Holds Steady

Stocks Hit All-Time High as Fed Holds Steady

AP (Sep. 17, 2014) — The Federal Reserve signaled Wednesday that it plans to keep a key interest rate at a record low because a broad range of U.S. economic measures remain subpar. Stocks hit an all-time high on the news. (Sept. 17) Video provided by AP
Powered by NewsLook.com
Space Race Pits Bezos Vs Musk

Space Race Pits Bezos Vs Musk

Reuters - Business Video Online (Sep. 16, 2014) — Amazon CEO Jeff Bezos' startup will team up with Boeing and Lockheed to develop rocket engines as Elon Musk races to have his rockets certified. Fred Katayama reports. Video provided by Reuters
Powered by NewsLook.com
MIT's Robot Cheetah Unleashed — Can Now Run, Jump Freely

MIT's Robot Cheetah Unleashed — Can Now Run, Jump Freely

Newsy (Sep. 16, 2014) — MIT developed a robot modeled after a cheetah. It can run up to speeds of 10 mph, though researchers estimate it will eventually reach 30 mph. Video provided by Newsy
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:
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