Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

World record for the entanglement of twisted light quanta

02.11.2012
To this end, the researchers developed a new method for entangling single photons which gyrate in opposite directions.
This result is a first step towards entangling and twisting even macroscopic, spatially separated objects in two different directions. The researchers at the Vienna Center for Quantum Science and Technology (VCQ), situated at the University of Vienna, and the Institute for Quantum Optics and Quantum Information (IQOQI) at the Austrian Academy of Sciences have were able to get their pioneering results published in the current issue of the renowned scientific journal Science.

Quantum physics is usually considered to be the theory of extremely lightweight objects, such as atoms or photons, or of exceptionally small units, namely very small quantum numbers. One of the most fascinating phenomena of quantum physics is that of entanglement. Entangled quanta of light behave as if able to influence each other – even as they are spatially separated.

False-color image of a laser beam exhibiting a superposition of 100 right-handed and 100 left-handed quanta of orbital angular momenta, resulting in 100+100=200 bright spots on the inner ring

Credit: Robert Fickler, University of Vienna


A long-exposure photo of laser light in 'donut modes' (light beams with no intensity in the middle).

Credit: Robert Fickler, University of Vienna

The question of whether or not entanglement is limited to tiny objects or very small quantum numbers came up already in the early days of quantum physics. Now, the Vienna group has taken the first step for testing quantum mechanical entanglement with rotating photons.

To illustrate, a quantum mechanical figure skater would have the uncanny ability to pirouette both clockwise and counter-clockwise simultaneously. Moreover, the direction of her rotations would be correlated with the twirls of another, entangled, skater – even if the two ice dancers whirl far removed from each other, in ice rinks on different continents.

The faster the two quantum skaters pirouette, the larger is the quantum number of their rotation direction, the so-called angular momentum. "In our experiment, we entangled the largest quantum numbers of any kind of particle ever measured," declares Zeilinger with a wry smile.

Could quantum ice dancers exist in reality?

It has been common knowledge for about 20 years now that theoretically, there is no upper limit for the angular momentum of photons. Previous experiments, however, have been limited, due to physical restrictions, to very weak angular momentum and small quantum numbers. In the Vienna experiment, it is theoretically possible to create entanglement regardless of the strength of the angular momentum or the scale of its quantum number. "Only our limited technical means stop us from creating entanglement with twisted photons that could be sensed even with bare hands," states Robert Fickler, the main author of the current Science publication. And so, the researchers have demonstrated that it is possible in principle to twirl entangled ice skaters simultaneously both in clockwise and counter-clockwise directions. In practice, a number of major challenges need to be addressed before such an experiment can be realized with macroscopic objects.

From fundamental research to technical applications

In addition to the fundamental issue of the limits of macroscopic entanglement, the physicists address possibilities of potential applications. They are, for example, able to use the created photons for very precise angular measurements already at low intensities of light. This feature is of advantage in particular when investigating light sensitive materials, as for example some biological substances. "The special features of entanglement provide the fantastic possibility to perform such measurements from arbitrary distances and without any contact whatsoever with the measured object, or even at a point in time that lies in the future!" Fickler explains.

This research was supported by the European Research Council (ERC) and the Austrian Science Fund (FWF).

Publication:
Quantum Entanglement of High Angular Momenta
Robert Fickler, Radek Lapkiewicz, William N. Plick, Mario Krenn, Christoph Schaeff, Sven Ramelow, Anton Zeilinger to be published in Science/ 2nd november issue.
Further information:
Research Group Quantum Optics, Quantum Nanophysics & Quantum Information, Faculty of Physics, University of Vienna and Institute for Quantum Optics and Quantum Information (IQOQI), Austrian Academy of Sciences: http://www.quantum.at/ Vienna Center for Quantum Science and Technology (VCQ): http://vcq.quantum.at/
Contact scientist:
Dipl. Phys. Robert Fickler
Quantum Optics, Quantum Nanophysics & Quantum Information
Faculty of Physics, University of Vienna
Institute for Quantum Optics and Quantum Information (ÖAW)
Boltzmanngasse 3, A-1090 Vienna, Austria
T 43-142-772-9568
robert.fickler@univie.ac.at
Further enquiry note:
Verena Bock
Office Anton Zeilinger
Quantum Optics, Quantum Nanophysics & Quantum Information
Faculty of Physics, University of Vienna
Institute for Quantum Optics and Quantum Information (ÖAW)
Boltzmanngasse 3, A-1090 Vienna, Austria
T 43-142-775-1166
zeilinger-office@univie.ac.at

Veronika Schallhart | EurekAlert!
Further information:
http://www.univie.ac.at

More articles from Physics and Astronomy:

nachricht CCNY-Yale researchers make shape shifting cell breakthrough
12.12.2018 | City College of New York

nachricht Electronic evidence of non-Fermi liquid behaviors in an iron-based superconductor
11.12.2018 | Science China Press

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: Lethal combination: Drug cocktail turns off the juice to cancer cells

A widely used diabetes medication combined with an antihypertensive drug specifically inhibits tumor growth – this was discovered by researchers from the University of Basel’s Biozentrum two years ago. In a follow-up study, recently published in “Cell Reports”, the scientists report that this drug cocktail induces cancer cell death by switching off their energy supply.

The widely used anti-diabetes drug metformin not only reduces blood sugar but also has an anti-cancer effect. However, the metformin dose commonly used in the...

Im Focus: New Foldable Drone Flies through Narrow Holes in Rescue Missions

A research team from the University of Zurich has developed a new drone that can retract its propeller arms in flight and make itself small to fit through narrow gaps and holes. This is particularly useful when searching for victims of natural disasters.

Inspecting a damaged building after an earthquake or during a fire is exactly the kind of job that human rescuers would like drones to do for them. A flying...

Im Focus: Topological material switched off and on for the first time

Key advance for future topological transistors

Over the last decade, there has been much excitement about the discovery, recognised by the Nobel Prize in Physics only two years ago, that there are two types...

Im Focus: Researchers develop method to transfer entire 2D circuits to any smooth surface

What if a sensor sensing a thing could be part of the thing itself? Rice University engineers believe they have a two-dimensional solution to do just that.

Rice engineers led by materials scientists Pulickel Ajayan and Jun Lou have developed a method to make atom-flat sensors that seamlessly integrate with devices...

Im Focus: Three components on one chip

Scientists at the University of Stuttgart and the Karlsruhe Institute of Technology (KIT) succeed in important further development on the way to quantum Computers.

Quantum computers one day should be able to solve certain computing problems much faster than a classical computer. One of the most promising approaches is...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

ICTM Conference 2019: Digitization emerges as an engineering trend for turbomachinery construction

12.12.2018 | Event News

New Plastics Economy Investor Forum - Meeting Point for Innovations

10.12.2018 | Event News

EGU 2019 meeting: Media registration now open

06.12.2018 | Event News

 
Latest News

New discoveries predict ability to forecast dementia from single molecule

12.12.2018 | Health and Medicine

CCNY-Yale researchers make shape shifting cell breakthrough

12.12.2018 | Physics and Astronomy

Pain: Perception and motor impulses arise in the brain independently of one another

12.12.2018 | Health and Medicine

VideoLinks
Science & Research
Overview of more VideoLinks >>>