Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Production Of High-Fidelity Entangled Photons Exceeds 1 Million Per Second

16.07.2004


Like virtuosos tuning their violins, researchers at the University of Illinois at Urbana-Champaign have tuned their instruments and harmonized the production of entangled photons, pushing rates to more than 1 million pairs per second.

The brighter and purer entangled states could assist researchers in applications involving quantum information processing - such as quantum computation, teleportation and cryptography - and help scientists better understand the mysterious transition from quantum mechanics to classical physics.

"Entangled states are the quintessential feature of quantum mechanics," said Paul Kwiat, a John Bardeen Professor of Electrical and Computer Engineering and Physics at Illinois. "All the manifestations of quantum mechanics in the world around us arise from the basic but bizarre coupling that exists between entangled particles."



For example, the properties of entangled photons are inextricably linked to each other, even if the photons are located on opposite sides of the galaxy. To study this "correlation at a distance," Kwiat and graduate students Joseph Altepeter and Evan Jeffrey produce pairs of polarization-entangled photons by passing a laser pulse through two adjacent nonlinear crystals.

"You can think of polarization as the ’wiggle’ direction of the photon - either horizontal, vertical or diagonal," Kwiat said. "As soon as you determine the wiggle direction of one photon in an entangled pair, you immediately know the wiggle direction of the other photon, no matter how far apart they are."

A major production problem, however, is that entangled photons are emitted in many directions and with a wide range of polarization phase relationships, each acting like an individual singer in a large choir.

"Instead of hearing a soloist hit one note, we were hearing many choir members, some of whom were singing off-key," Kwiat said.

The trick was to come up with a way of tuning the system. "We found that we could pass the photons through another crystal - one that has a different phase profile - to compensate for the different phase relationships," Kwiat said. "The dissonance is corrected and the system becomes harmonized."

In the same manner as a corrector lens in a telescope removes chromatic aberration and improves image quality, the researchers’ special birefringent crystal removes distortions in the quality of the entanglement. "After the compensator crystal, the photons are all entangled in exactly the same way," Altepeter said. "We can open the iris and get more than 1 million useful pairs per second."

Ultrabright, ultrapure sources of entangled photons are essential for pursuing quantum computing and quantum networks, as a resource for teleportation in quantum communication, and for sending more information faster by means of quantum cryptography. High fidelity quantum states can also provide researchers with a clearer picture of how the universe works on a very fundamental level.

"Using a low-brightness source is like looking into the quantum world through a foggy window," Altepeter said. "With a bright, pure source, we have a very clear window that allows us to see phenomena we couldn’t see before."

The ultimate goal is to understand and develop an intuition for the quantum nature of reality, said Kwiat, who will report the team’s findings at the International Conference on Quantum Communication, Measurement and Computing, to be held July 25-29 in Glasgow, United Kingdom. "Higher production rates of nearly perfectly entangled photons will help us better understand the rules of the quantum universe, how to navigate that universe, and how to characterize it in a very precise way."

The work was funded by the National Science Foundation, the Army Research Office, and the Advanced Research and Development Activity.

James E. Kloeppel | UIUC News Bureau
Further information:
http://www.uiuc.edu

More articles from Physics and Astronomy:

nachricht Molecule flash mob
19.01.2017 | Technische Universität Wien

nachricht Magnetic moment of a single antiproton determined with greatest precision ever
19.01.2017 | Johannes Gutenberg-Universität Mainz

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: Traffic jam in empty space

New success for Konstanz physicists in studying the quantum vacuum

An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Sustainable Water use in Agriculture in Eastern Europe and Central Asia

19.01.2017 | Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

 
Latest News

New Study Will Help Find the Best Locations for Thermal Power Stations in Iceland

19.01.2017 | Earth Sciences

Not of Divided Mind

19.01.2017 | Life Sciences

Molecule flash mob

19.01.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>