Free Newsletters - Space News - Defense Alert - Environment Report - Energy Monitor
. 24/7 Space News .




CHIP TECH
Quantum Communication: Each Photon Counts
by Staff Writers
Karlsruhe, Germany (SPX) Jan 29, 2013


The single-photon detector is characterized by five convincing factors: 91% detection efficiency; direct integration on chip; counting rates on a Gigahertz scale; high timing resolution and negligible dark counting rates. Source: KIT/CFN.

Ultrafast, efficient, and reliable single-photon detectors are among the most sought-after components in photonics and quantum communication, which have not yet reached maturity for practical application.

Physicist Dr. Wolfram Pernice of the Karlsruhe Institute of Technology (KIT), in cooperation with colleagues at Yale University, Boston University, and Moscow State Pedagogical University, achieved the decisive breakthrough by integrating single-photon detectors with nanophotonic chips. The detector combines near-unity detection efficiency with high timing resolution and has a very low error rate.

Without reliable detection of single photons, it is impossible to make real use of the latest advances in optical data transmission or quantum computation; it is like having no analog-digital converter in a conventional computer to determine whether the applied voltage stands for 0 or 1.

Although a number of different single-photon detector models have been developed over the past few years, thus far, none have provided satisfactory performance.

Several new ideas and advanced developments went into the prototype developed within the "Integrated Quantum Photonics" project at the DFG Center of Functional Nanostructures (CFN). The new single-photon detector, tested in the telecommunications wavelength range, achieves a previously unattained detection efficiency of 91%.

The detector was realized by fabricating superconducting nanowires directly on top of a nanophotonic waveguide. This geometry can be compared to a tube that conducts light, around which a wire in a superconducting state is wound and, as such, has no electric resistivity.

The nanometer-sized wire made of niobium nitride absorbs photons that propagate along the waveguide. When a photon is absorbed, superconductivity is lost, which is detected as an electric signal. The longer the tube, the higher is the detection probability. The lengths involved are in the micrometer range.

A special feature of the detector is its direct installation on the chip, which allows for it to be replicated at random. The single-photon detectors built thus far were stand-alone units, which were connected to chips with optical fibers.

Arrangements of that type suffer from photons being lost in the fiber connection or being absorbed in other ways. These loss channels do not exist in the detector that is now fully embedded in a silicon photonic circuit. In addition to high detection efficiency, this gives rise to a remarkably low dark count rate.

Dark counts arise when a photon is detected erroneously: for instance, because of a spontaneous emission, an alpha particle, or a spurious field. The new design also provides ultrashort timing jitter of 18 picoseconds, which is 18 times 10-12 seconds.

The novel solution also makes it possible to integrate several hundreds of these detectors on a single chip. This is a basic precondition for future use in optical quantum computers.

The detector demonstrated in this study was designed to work at wavelengths in the Telekom bandwidth. The same detector architecture can also be used for wavelengths in the range of visible light. This would allow the principle to be employed in analyses of all structures that emit little light, i.e., photons, such as single molecules or bacteria.

The results have been published by Nature Communications (doi:10.1038/ncomms2307).

.


Related Links
DFG Center of Functional Nanostructures
Karlsruhe Institute of Technology
Computer Chip Architecture, Technology and Manufacture
Nano Technology News From SpaceMart.com






Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle




Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News





CHIP TECH
Organic ferroelectric molecule shows promise for memory chips, sensors
Seattle WA (SPX) Jan 29, 2013
At the heart of computing are tiny crystals that transmit and store digital information's ones and zeroes. Today these are hard and brittle materials. But cheap, flexible, nontoxic organic molecules may play a role in the future of hardware. A team led by the University of Washington in Seattle and the Southeast University in China discovered a molecule that shows promise as an organic alt ... read more


CHIP TECH
US, Europe team up for moon fly-by

Russia to Launch Lunar Mission in 2015

US, Europe team up for moon fly-by

Mission would drag asteroid to the moon

CHIP TECH
Is there life on Mars?

Opportunity At Work At Whitewater Lake

Thawing Dry Ice Drives Groovy Action On Mars

Mars Rover Curiosity Uses Arm Camera at Night

CHIP TECH
TDRS-K Offers Upgrade to Vital Communications Net

How to predict the future of technology

Iran Manufacturing Hi-Tech Spacesuits

TDRS-K Offers Upgrade to Vital Communications Net

CHIP TECH
Reshuffle for Tiangong

China to launch 20 spacecrafts in 2013

Mr Xi in Space

China plans manned space launch in 2013: state media

CHIP TECH
NASA to Send Inflatable Pod to International Space Station

ISS to get inflatable module

ESA workhorse to power NASA's Orion spacecraft

Competition Hopes To Fine Tune ISS Solar Array Shadowing

CHIP TECH
Russia Set for Year's First Baikonur Space Launch Feb. 5

First Ariane 5 For 2013 Ready For Loading

Azerspace And Africasat-1a "fit" for Ariane 5 launch

NASA Selects Experimental Commercial Suborbital Flight Payloads

CHIP TECH
The Origin And Maintenance Of A Retrograde Exoplanet

New Evidence Indicates Auroras Occur Outside Our Solar System

Glitch has space telescope shut down

Earth-size planets common in galaxy

CHIP TECH
Laser-Plasma Process Gives Nanohybrid Remarkable Properties

DNA and quantum dots: All that glitters is not gold

Liquid metal makes silicon crystals at record low temperatures

Supercomputer sets computing record




The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA Portal Reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement