. 24/7 Space News .
TIME AND SPACE
The atom without properties
by Staff Writers
Basel, Switzerland (SPX) Apr 26, 2016


A microchip is used to trap a cloud of ultracold atoms and to entangle the atoms' magnetic moments. Image courtesy University of Basel, Department of Physics. For a larger version of this image please go here.

The microscopic world is governed by the rules of quantum mechanics, where the properties of a particle can be completely undetermined and yet strongly correlated with those of other particles. Physicists from the University of Basel have observed these so-called Bell correlations for the first time between hundreds of atoms. Their findings are published in the scientific journal Science.

Everyday objects possess properties independently of each other and regardless of whether we observe them or not. Einstein famously asked whether the moon still exists if no one is there to look at it; we answer with a resounding yes. This apparent certainty does not exist in the realm of small particles. The location, speed or magnetic moment of an atom can be entirely indeterminate and yet still depend greatly on the measurements of other distant atoms.

Experimental test of Bell correlations
With the (false) assumption that atoms possess their properties independently of measurements and independently of each other, a so-called Bell inequality can be derived. If it is violated by the results of an experiment, it follows that the properties of the atoms must be interdependent.

This is described as Bell correlations between atoms, which also imply that each atom takes on its properties only at the moment of the measurement. Before the measurement, these properties are not only unknown - they do not even exist.

A team of researchers led by professors Nicolas Sangouard and Philipp Treutlein from the University of Basel, along with colleagues from Singapore, have now observed these Bell correlations for the first time in a relatively large system, specifically among 480 atoms in a Bose-Einstein condensate.

Earlier experiments showed Bell correlations with a maximum of four light particles or 14 atoms. The results mean that these peculiar quantum effects may also play a role in larger systems.

Large number of interacting particles
In order to observe Bell correlations in systems consisting of many particles, the researchers first had to develop a new method that does not require measuring each particle individually - which would require a level of control beyond what is currently possible. The team succeeded in this task with the help of a Bell inequality that was only recently discovered.

The Basel researchers tested their method in the lab with small clouds of ultracold atoms cooled with laser light down to a few billionths of a degree above absolute zero. The atoms in the cloud constantly collide, causing their magnetic moments to become slowly entangled.

When this entanglement reaches a certain magnitude, Bell correlations can be detected. Author Roman Schmied explains: "One would expect that random collisions simply cause disorder. Instead, the quantum-mechanical properties become entangled so strongly that they violate classical statistics."

More specifically, each atom is first brought into a quantum superposition of two states. After the atoms have become entangled through collisions, researchers count how many of the atoms are actually in each of the two states.

This division varies randomly between trials. If these variations fall below a certain threshold, it appears as if the atoms have 'agreed' on their measurement results; this agreement describes precisely the Bell correlations.

New scientific territory
The work presented, which was funded by the National Centre of Competence in Research Quantum Science and Technology (NCCR QSIT), may open up new possibilities in quantum technology; for example, for generating random numbers or for quantum-secure data transmission.

New prospects in basic research open up as well: "Bell correlations in many-particle systems are a largely unexplored field with many open questions - we are entering uncharted territory with our experiments," says Philipp Treutlein.


Thanks for being here;
We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain.

With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords.

Our news coverage takes time and effort to publish 365 days a year.

If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.
SpaceDaily Contributor
$5 Billed Once


credit card or paypal
SpaceDaily Monthly Supporter
$5 Billed Monthly


paypal only


.


Related Links
University of Basel
Understanding Time and Space






Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle

Previous Report
TIME AND SPACE
Zip software can detect the quantum-classical boundary
Singapore (SPX) Apr 25, 2016
Quantum physics has a reputation for being mysterious and mathematically challenging. That makes it all the more surprising that a new technique to detect quantum behaviour relies on a familiar tool: a "zip" program you might have installed on your computer. "We found a new way to see a difference between the quantum universe and a classical one, using nothing more complex than a compressi ... read more


TIME AND SPACE
First rocket made ready for launch at Vostochny spaceport

Supernova iron found on the moon

Russia to shift all Lunar launches to Vostochny Cosmodrome

Lunar lava tubes could help pave way for human colony

TIME AND SPACE
Mars' surface revealed in unprecedented detail

NASA rocket fuel pump tests pave way for methane-fueled Mars lander

Opportunity completes mini-walkabout

Curiosity Mars Rover crosses rugged plateau

TIME AND SPACE
Tech industry titans urge US to better fund science ed

When technology bites back

Menstruation in spaceflight: Options for astronauts

Space Subcommittee examines commercial challenges

TIME AND SPACE
China can meet Chile's satellite needs: ambassador

South China city gears up for satellite tourism

China targets 2020 Mars mission launch: official

China testing own reusable rocket technologies

TIME AND SPACE
15 years of Europe on the International Space Station

US-Russia Space Projects Set Example of Good Cooperation

Russia, US discuss boosting efficiency of cooperation at ISS

BEAM successfully installed to the International Space Station

TIME AND SPACE
New small launch vehicles

Russia May Launch Upgraded Proton-M Rocket on May28

SpaceX vows to send capsule to Mars by 2018

Soyuz demonstrates Arianespace mission flexibility

TIME AND SPACE
Kepler spacecraft recovered and returned to the K2 Mission

Lone planetary-mass object found in family of stars

University of Massachusetts Lowell PICTURE-B Mission Completed

Stars strip away atmospheres of nearby super-Earths

TIME AND SPACE
Nano-magnets produce 3-dimensional images

Liquid spiral vortex discovered

New material combines useful, typically incompatible properties

Model makes designing new antennas orders of magnitude faster









The content herein, unless otherwise known to be public domain, are Copyright 1995-2024 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. All articles labeled "by Staff Writers" include reports supplied to Space Media Network by industry news wires, PR agencies, corporate press officers and the like. Such articles are individually curated and edited by Space Media Network staff on the basis of the report's information value to our industry and professional readership. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. General Data Protection Regulation (GDPR) Statement Our advertisers use various cookies and the like to deliver the best ad banner available at one time. All network advertising suppliers have GDPR policies (Legitimate Interest) that conform with EU regulations for data collection. By using our websites you consent to cookie based advertising. If you do not agree with this then you must stop using the websites from May 25, 2018. Privacy Statement. Additional information can be found here at About Us.