Subscribe to our free daily newsletters
. 24/7 Space News .




Subscribe to our free daily newsletters



TIME AND SPACE
'Find the Lady' in the quantum world
by Staff Writers
Bonn, Germany (SPX) Oct 18, 2017


Two atoms, initially prepared in different locations, exchange their positions along the blue path, whereas no exchange occurs along the red path. In quantum mechanics, it is possible that the atoms take simultaneously both ways. As a result of such a tricky manipulation, it is fundamentally impossible at the end to determine the origin of the atoms, and their spin orientations (denoted by arrows) become entangled.

An international team of researchers has proposed a new way to make atoms or ions indistinguishable by swapping their positions. These particles are then expected to exhibit exotic properties. The study involved physicists from the University of Bonn, the Austrian Academy of Sciences, and the University of California. The work has now been published in Physical Review Letters.

Imagine that you are playing the game of 'Find the Lady' - in fact, a very simple version of it: The croupier is no hardened con artist, but rather a thoroughly honest woman. And on the table in front of her are just two cups, not three. These are made from black plastic and look so darned alike that - try as you might - you cannot distinguish one from the other.

The croupier now begins to move both cups backward and forward. Her moves are very fast and dexterous. Nevertheless, with a little concentration, you manage to follow her moves. At the end, you can correctly state which of the cups was originally on the left and which on the right.

But what would happen if you close your eyes when the cups are being moved? In this case, you can only guess: after all, to you, both cups look completely identical. Of course, they aren't really so: cup 1 remains cup 1, no matter how often it changes places with cup 2.

However, in the world of the smallest things, experiments can be performed in which the thing of identity is not that clear. Playing a game such as 'Find the Lady' in the quantum world has now been proposed by physicists at the Institute of Applied Physics (IAP) of the University of Bonn together with their colleagues from Austria and the USA.

In different places at the same time
In the quantum world, the cups are replaced by two atoms that are exactly in the same atomic state. "Such atoms can be produced in specialized laboratories with state-of-the-art techniques," explains Prof. Dieter Meschede from the IAP. "They are actually completely the same and only differ due to the position at which they are located."

When you play 'Find the Lady' in the world of atoms, you have some extra freedom. For instance, researchers can count on the quantum mechanical phenomenon according to which particles can be in two different places at the same time. By cleverly using this phenomenon, atom 1 and 2 can, with a certain amount of luck, swap places without anyone noticing.

In other words: at the end of the quantum manipulation, the observer has no way to say - as a matter of principle - whether atom 1 is actually still atom 1 or whether it has been swapped with atom 2. For standard cups, it would still be possible to tell them apart reliably using their tiniest differences such as a microscopically small dent. This is not the case for identically prepared atoms; they are exactly the same. "At the end of the experiment, it is thus no longer possible - in whatever form - to identify which of the two atoms is number 1 and which is number 2," explains Dr. Andrea Alberti from the IAP.

This also has philosophical implications. The German philosopher Gottfried Wilhelm Leibniz (1646-1716) is credited with the assertion that two objects are identical when no differences can be discerned between them. Following Leibniz's logic, the switched atoms must have then lost part of their individuality: they are two, yet they are somehow one.

Astoundingly, both of them are also 'connected' to each other after switching places: certain properties of both particles such as the spin - the direction of rotation of an atom - depend upon both particles. If you observe the spin orientation of atom 1, then you will immediately know the spin orientation of atom 2 - even without directly observing it. "It is as if you throw two coins independently of each other," explains Andrea Alberti. "If one coin shows heads, then this must also be the case for the other." Physicists talk of 'entanglement'.

The IAP researchers are currently working on putting their theoretical proposal into practice. The experiment can also be performed in a modified form with other particles such as ions - a route that the colleagues at the Institute for Quantum Optics and Quantum Information in Innsbruck of the Austrian Academy of Sciences want to take. "We expect from these studies, in which we control with high precision exactly two quantum particles, new findings on the fundamental quantum mechanical exchange principle," hopes Alberti.

Research Report: Revealing Quantum Statistics with a Pair of Distant Atoms

TIME AND SPACE
JILA's 3-D quantum gas atomic clock offers new dimensions in measurement
Washington DC (SPX) Oct 09, 2017
JILA physicists have created an entirely new design for an atomic clock, in which strontium atoms are packed into a tiny three-dimensional (3-D) cube at 1,000 times the density of previous one-dimensional (1-D) clocks. In doing so, they are the first to harness the ultra-controlled behavior of a so-called "quantum gas" to make a practical measurement device. With so many atoms completely i ... read more

Related Links
University of Bonn
Understanding Time and Space


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

Comment using your Disqus, Facebook, Google or Twitter login.

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

TIME AND SPACE
US spacewalkers install 'new eyes' at space station

NASA May Extend BEAM's Time on the International Space Station

USNO Astronomers Measure New Distances To Nearby Stars

OECD calls for tourism to be more sustainable

TIME AND SPACE
DARPA Awards Aerojet Rocketdyne Contract to Develop Hypersonic Advanced Full Range Engine

ASPIRE Successfully Launches from NASA Wallops

Arianespace to launch COSMO-SkyMed satellites manufactured by Thales

New Zealand opens first rocket launch site

TIME AND SPACE
Russian Space Research Institute Announces July 2020 Date for Mission to Mars

ASU examines Mars' moon Phobos in a different light

Mars Study Yields Clues to Possible Cradle of Life

Another Chance to Put Your Name on Mars

TIME AND SPACE
China launches three satellites

Mars probe to carry 13 types of payload on 2020 mission

UN official commends China's role in space cooperation

China's cargo spacecraft separates from Tiangong-2 space lab

TIME AND SPACE
SpaceX launches 10 satellites for Iridium mobile network

Lockheed Martin Completes First Flexible Solar Array for LM 2100 Satellite

GomSpace and Luxembourg to develop space activities in the Grand Duchy

Private companies are launching a new space race

TIME AND SPACE
Understanding rare earth emulsions

Oculus unveils standalone virtual reality headset

New test opens path for better 2-D catalysts

Thales demos capability of ballistic missile tracking radar

TIME AND SPACE
Are Self-Replicating Starships Practical

New telescope attachment allows ground-based observations of new worlds

Biomarker Found In Space Complicates Search For Life On Exoplanets

The Super-Earth that Came Home for Dinner

TIME AND SPACE
Helicopter test for Jupiter icy moons radar

Solving the Mystery of Pluto's Giant Blades of Ice

Global Aerospace Corporation to present Pluto lander concept to NASA

Pluto features given first official names




Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News






The content herein, unless otherwise known to be public domain, are Copyright 1995-2017 - 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. Privacy Statement