Featured Research

from universities, journals, and other organizations

New ultrabright source of entangled photon pairs

Date:
July 11, 2010
Source:
CNRS (Délégation Paris Michel-Ange)
Summary:
At the very heart of applications such as quantum cryptography, computation and teleportation lies a fascinating phenomenon known as "entanglement". Two photons are entangled if the properties of one depend on those of the other, whatever the distance separating them. A new source of entangled photons twenty times brighter than all existing systems has been developed by a team in France. This novel device is capable of considerably boosting the rate of quantum communications and constitutes a key component in future quantum logic processes.

This image represents, in the top right hand corner, the new component produced in this experiment: two pillars of micrometric size are coupled to form the "photonic molecule". The semiconductor quantum dot (of nanometric size) is inserted into one of the pillars (visible as the bright spot in the right hand pillar). The lower part of the image shows the radiation pattern of the entangled photons emitted by the component.
Credit: Copyright Jean-Louis Le Hir

At the very heart of applications such as quantum cryptography, computation and teleportation lies a fascinating phenomenon known as "entanglement." Two photons are entangled if the properties of one depend on those of the other, whatever the distance separating them.

Related Articles


A new source of entangled photons twenty times brighter than all existing systems has been developed by a team from the Laboratoire de Photonique et de Nano-structures (LPN) of CNRS. This novel device is capable of considerably boosting the rate of quantum communications and constitutes a key component in future quantum logic processes. These results are published in the journal Nature (July 8, 2010).

Take a photon in Paris and another in Tokyo: if they are "entangled," they are interdependent and measuring the properties of one makes it possible to know the properties of the other instantly, whatever the distance separating them. This mysterious property, known as "entanglement," has far reaching application potential in information fields such as quantum cryptography, quantum computation and quantum teleportation. Normally, researchers use sources of entangled photon pairs that are easy to put in place (a laser transforming a photon into two photons of different color) but with very low brightness: less than one pulse out of 100 actually contains a pair of entangled photons, which considerably restricts the rate of any quantum communication. In addition, the size of such sources means they cannot be easily integrated into microsystems.

A team from the Laboratoire de Photonique et de Nano-structures (LPN) of CNRS has developed a light source of entangled photons twenty times brighter than all existing systems. The researchers have invented a novel "photonic molecule" system in which a semiconductor quantum dot1 emits a pair of entangled photons per excitation pulse. This photonic molecule constitutes a trap for each of the photons of the pair and allows them to be collected efficiently. This new source operates at a rate of one pair of photons collected every 8 pulses (compared to less than one pair every 100 pulses so far).

In the long run, the researchers should be able to reach a rate close to one pair of photons per pulse. This device could make it possible to manufacture electroluminescent diodes of entangled photon pairs, with rates close to one gigahertz (in other words around on billion hertz). Moreover, the LPN scientists have also shown that the use of this "photonic molecule" concept allows the quality of the entanglement of the emitted photon pairs to be improved.

Note:

(1) Quantum dots are nanocrystals of semiconductor material, the dimensions of which are typically 20 nanometers (i.e. 20 billionths of a meter). By virtue of its size, a quantum dot behaves like a potential well, which confines carriers within the three dimensions of a space typically of the order of several tens of nanometers in a semiconductor. This confinement gives the quantum dots properties similar to those of an atom.


Story Source:

The above story is based on materials provided by CNRS (Délégation Paris Michel-Ange). Note: Materials may be edited for content and length.


Journal Reference:

  1. Adrien Dousse, Jan Suffczy%u0144ski, Alexios Beveratos, Olivier Krebs, Aristide Lemaître, Isabelle Sagnes, Jacqueline Bloch, Paul Voisin, Pascale Senellart. Ultrabright source of entangled photon pairs. Nature, 2010; 466 (7303): 217 DOI: 10.1038/nature09148

Cite This Page:

CNRS (Délégation Paris Michel-Ange). "New ultrabright source of entangled photon pairs." ScienceDaily. ScienceDaily, 11 July 2010. <www.sciencedaily.com/releases/2010/07/100709083843.htm>.
CNRS (Délégation Paris Michel-Ange). (2010, July 11). New ultrabright source of entangled photon pairs. ScienceDaily. Retrieved October 24, 2014 from www.sciencedaily.com/releases/2010/07/100709083843.htm
CNRS (Délégation Paris Michel-Ange). "New ultrabright source of entangled photon pairs." ScienceDaily. www.sciencedaily.com/releases/2010/07/100709083843.htm (accessed October 24, 2014).

Share This



More Matter & Energy News

Friday, October 24, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Police Testing New Gunfire Tracking Technology

Police Testing New Gunfire Tracking Technology

AP (Oct. 24, 2014) — A California-based startup has designed new law enforcement technology that aims to automatically alert dispatch when an officer's gun is unholstered and fired. Two law enforcement agencies are currently testing the technology. (Oct. 24) Video provided by AP
Powered by NewsLook.com
3D Printed Instruments Make Sweet Music in Sweden

3D Printed Instruments Make Sweet Music in Sweden

Reuters - Innovations Video Online (Oct. 23, 2014) — Students from Lund University's Malmo Academy of Music are believed to be the world's first band to all use 3D printed instruments. The guitar, bass guitar, keyboard and drums were built by Olaf Diegel, professor of product development, who says 3D printing allows musicians to design an instrument to their exact specifications. Matthew Stock reports. Video provided by Reuters
Powered by NewsLook.com
Chameleon Camouflage to Give Tanks Cloaking Capabilities

Chameleon Camouflage to Give Tanks Cloaking Capabilities

Reuters - Innovations Video Online (Oct. 22, 2014) — Inspired by the way a chameleon changes its colour to disguise itself; scientists in Poland want to replace traditional camouflage paint with thousands of electrochromic plates that will continuously change colour to blend with its surroundings. The first PL-01 concept tank prototype will be tested within a few years, with scientists predicting that a similar technology could even be woven into the fabric of a soldiers' clothing making them virtually invisible to the naked eye. Matthew Stock reports. Video provided by Reuters
Powered by NewsLook.com
Jet Sales Lift Boeing Profit 18 Pct.

Jet Sales Lift Boeing Profit 18 Pct.

Reuters - Business Video Online (Oct. 22, 2014) — Strong jet demand has pushed Boeing to raise its profit forecast for the third time, but analysts were disappointed by its small cash flow. Fred Katayama reports. Video provided by Reuters
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:

Strange & Offbeat Stories

 

Space & Time

Matter & Energy

Computers & Math

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins