Featured Research

from universities, journals, and other organizations

Laser-like photons signal major step towards quantum 'Internet'

Date:
March 19, 2013
Source:
University of Cambridge
Summary:
The realization of quantum networks is one of the major challenges of modern physics. Now, new research shows how high-quality photons can be generated from "solid-state" chips, bringing us closer to the quantum "Internet."

An artist's impression of distributed qubits (the bright spots) linked to each other via photons (the light beams). The colors of the beams represent that the optical frequency of the photons in each link can be tailored to the needs of the network.
Credit: Mete Atature

The realisation of quantum networks is one of the major challenges of modern physics. Now, new research shows how high-quality photons can be generated from 'solid-state' chips, bringing us closer to the quantum 'internet'.

Related Articles


The number of transistors on a microprocessor continues to double every two years, amazingly holding firm to a prediction by Intel co-founder Gordon Moore almost 50 years ago.

If this is to continue, conceptual and technical advances harnessing the power of quantum mechanics in microchips will need to be investigated within the next decade. Developing a distributed quantum network is one promising direction pursued by many researchers today.

A variety of solid-state systems are currently being investigated as candidates for quantum bits of information, or qubits, as well as a number of approaches to quantum computing protocols, and the race is on for identifying the best combination. One such qubit, a quantum dot, is made of semiconductor nanocrystals embedded in a chip and can be controlled electro-optically.

Single photons will form an integral part of distributed quantum networks as flying qubits. First, they are the natural choice for quantum communication, as they carry information quickly and reliably across long distances. Second, they can take part in quantum logic operations, provided all the photons taking part are identical.

Unfortunately, the quality of photons generated from solid-state qubits, including quantum dots, can be low due to decoherence mechanisms within the materials. With each emitted photon being distinct from the others, developing a quantum photonic network faces a major roadblock.

Now, researchers from the Cavendish Laboratory at Cambridge University have implemented a novel technique to generate single photons with tailored properties from solid-state devices that are identical in quality to lasers. Their research is published today in the journal Nature Communications.

As their photon source, the researchers built a semiconductor Schottky diode device containing individually addressable quantum dots. The transitions of quantum dots were used to generate single photons via resonance fluorescence -- a technique demonstrated previously by the same team.

Under weak excitation, also known as the Heitler regime, the main contribution to photon generation is through elastic scattering. By operating in this way, photon decoherence can be avoided altogether. The researchers were able to quantify how similar these photons are to lasers in terms of coherence and waveform -- it turned out they were identical.

"Our research has added the concepts of coherent photon shaping and generation to the toolbox of solid-state quantum photonics," said Dr Mete Atature from the Department of Physics, who led the research.

"We are now achieving a high-rate of single photons which are identical in quality to lasers with the further advantage of coherently programmable waveform -- a significant paradigm shift to the conventional single photon generation via spontaneous decay."

There are already protocols proposed for quantum computing and communication which rely on this photon generation scheme, and this work can be extended to other single photon sources as well, such as single molecules, colour centres in diamond and nanowires.

"We are at the dawn of quantum-enabled technologies, and quantum computing is one of many thrilling possibilities," added Atature.

"Our results in particular suggest that multiple distant qubits in a distributed quantum network can share a highly coherent and programmable photonic interconnect that is liberated from the detrimental properties of the chips. Consequently, the ability to generate quantum entanglement and perform quantum teleportation between distant quantum-dot spin qubits with very high fidelity is now only a matter of time."


Story Source:

The above story is based on materials provided by University of Cambridge. The original story is licensed under a Creative Commons Licence. Note: Materials may be edited for content and length.


Journal Reference:

  1. Clemens Matthiesen, Martin Geller, Carsten H. H. Schulte, Claire Le Gall, Jack Hansom, Zhengyong Li, Maxime Hugues, Edmund Clarke, Mete Atatόre. Phase-locked indistinguishable photons with synthesized waveforms from a solid-state source. Nature Communications, 2013; 4: 1600 DOI: 10.1038/ncomms2601

Cite This Page:

University of Cambridge. "Laser-like photons signal major step towards quantum 'Internet'." ScienceDaily. ScienceDaily, 19 March 2013. <www.sciencedaily.com/releases/2013/03/130319124214.htm>.
University of Cambridge. (2013, March 19). Laser-like photons signal major step towards quantum 'Internet'. ScienceDaily. Retrieved January 29, 2015 from www.sciencedaily.com/releases/2013/03/130319124214.htm
University of Cambridge. "Laser-like photons signal major step towards quantum 'Internet'." ScienceDaily. www.sciencedaily.com/releases/2013/03/130319124214.htm (accessed January 29, 2015).

Share This


More From ScienceDaily



More Computers & Math News

Thursday, January 29, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

'Brand Blocker' Glasses Blur Ads in Real Time

'Brand Blocker' Glasses Blur Ads in Real Time

Buzz60 (Jan. 28, 2015) — A team of college students design and build a pair of goggles that will obscure any corporate branding from your field of vision. Jen Markham (@jenmarkham) has the story. Video provided by Buzz60
Powered by NewsLook.com
iPhone Sales Give Apple Record Quarter

iPhone Sales Give Apple Record Quarter

AP (Jan. 28, 2015) — Apple says staggering consumer demand for new iPhones has helped the company report record-smashing earnings for its latest quarter and primed its stock for a rally. (Jan. 28) Video provided by AP
Powered by NewsLook.com
Google Fiber Pressures Incumbent ISPs With Latest Expansion

Google Fiber Pressures Incumbent ISPs With Latest Expansion

Newsy (Jan. 28, 2015) — Google’s newly announced Fiber cities put it in closer competition with the likes of AT&T and Time Warner Cable. Video provided by Newsy
Powered by NewsLook.com
Google High-Speed Service Coming to 4 Cities

Google High-Speed Service Coming to 4 Cities

AP (Jan. 28, 2015) — Google is expanding its fiber-optic high-speed internet service to four cities in the Southeastern US. The company selected Atlanta, Charlotte, Raleigh and Nashville and their surrounding communities. (Jan. 28) Video provided by AP
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