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 From rocks in Colorado, evidence of a 'chaotic solar system'
23.02.2017 | University of Wisconsin-Madison

nachricht Prediction: More gas-giants will be found orbiting Sun-like stars
22.02.2017 | Carnegie Institution for Science

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: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Stingless bees have their nests protected by soldiers

24.02.2017 | Life Sciences

New risk factors for anxiety disorders

24.02.2017 | Life Sciences

MWC 2017: 5G Capital Berlin

24.02.2017 | Trade Fair News

VideoLinks
B2B-VideoLinks
More VideoLinks >>>