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 Study offers new theoretical approach to describing non-equilibrium phase transitions
27.04.2017 | DOE/Argonne National Laboratory

nachricht SwRI-led team discovers lull in Mars' giant impact history
26.04.2017 | Southwest Research Institute

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: Making lightweight construction suitable for series production

More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.

Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...

Im Focus: Wonder material? Novel nanotube structure strengthens thin films for flexible electronics

Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.

"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

7th International Conference on Crystalline Silicon Photovoltaics in Freiburg on April 3-5, 2017

03.04.2017 | Event News

 
Latest News

Bare bones: Making bones transparent

27.04.2017 | Life Sciences

Study offers new theoretical approach to describing non-equilibrium phase transitions

27.04.2017 | Physics and Astronomy

From volcano's slope, NASA instrument looks sky high and to the future

27.04.2017 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>