Subscribe to our free daily newsletters
. 24/7 Space News .




Subscribe to our free daily newsletters



NANO TECH
Practical superconducting nanowire single photon detector highly efficient
by Staff Writers
Beijing, China (SPX) Nov 14, 2017


File image

Superconducting nanowire single-photon detectors (SNSPDs) offer significant improvement on detection efficiency (DE) compared to their semiconducting counterparts, having enabled many breakthrough applications in quantum information technologies.

The team headed by Prof. Lixing You from Shanghai Institute of Microsystem and Information Technology (SIMIT), Chinese Academy of Sciences (CAS) (also affiliated to CAS Center for Excellence in Superconducting Electronics (CENSE)) first demonstrated the fabrication and operation of a NbN-SNSPD with system detection efficiency over 90% at 2.1 K at a wavelength of 1550 nm, which paves the way for practical application of SNSPD (Figure 1).

The results were published recently on SCIENCE CHINA Physics, Mechanics and Astronomy [1] as a cover image story. Dr. Weijun Zhang is the first author and Dr. Lixing You is the corresponding author.

At 1550 nm, which is the most important wavelength for applications, the state of the art SNSPD made of WSi superconductor has reached a DE record of 93% [2], compared to InGaAs detector with DE ~30%. Unfortunately, WSi-SNSPD usually operates at sub-kelvin temperatures, requiring expensive and user unfriendly refrigeration equipment.

Extensive efforts are made on the development of SNSPDs based on NbN, targeted at operating temperature above 2K, accessible to inexpensive and user-friendly compact cryocoolers. With a decade research, the detection efficiency of NbN-SNSPDs were gradually increased to ~ 80%. However, further improvements are not reported. Achieving DE over 90% requires the simultaneous optimization of many different factors, including near perfect optical coupling, near perfect absorption, and near unity intrinsic quantum efficiency. Previous attempts at doing this have mostly been made through a process of trial and error.

This paper first reported a NbN-SNSPD system based on G-M cryocooler with system detection efficiency over 90% (at dark count rate of 10 Hz) at 2.1 K at a wavelength of 1550 nm. The efficiency of the device saturates to 92% when the temperature is lowered to 1.8 K.

The success of this device has been the result of using an integrated Distributed Bragg Reflector (DBR) cavity offering near unity refection at the interface, and through systematic optimization of the NbN nanowire's meandered geometry. The joint efforts enable researchers to simultaneously achieve the stringent requirements for coupling, absorption and intrinsic quantum efficiency.

What is more, the device exhibit timing jitters down to 79 ps, almost half that of previously reported WSi-SNSPD, promising additional advantages in applications requiring high timing precision. The devices have been applied to the quantum information frontier experiments in University of Science and Technology of China.

SNSPD with near unity detection efficiency operational on economical and user-friendly compact cryocooler will provide researchers a powerful and easy accessible tool, envisage further breakthrough in quantum information areas such as optical quantum computation/simulation, quantum key distribution etc., in a foreseeable near future.

Research paper

NANO TECH
Subset of carbon nanotubes poses cancer risk similar to asbestos in mice
Washington DC (SPX) Nov 09, 2017
Nanotechnology, the science of developing materials containing very small fibers, is having a growing influence on daily life. Now researchers have shown for the first time in mice that long and thin nanomaterials called carbon nanotubes may have the same carcinogenic effect as asbestos: they can induce the formation of mesothelioma. The findings were observed in 10%-25% of the 32 animals ... read more

Related Links
Science China Press
Nano Technology News From SpaceMart.com
Computer Chip Architecture, Technology and Manufacture


Thanks for being here;
We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain.

With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords.

Our news coverage takes time and effort to publish 365 days a year.

If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.

SpaceDaily Contributor
$5 Billed Once


credit card or paypal
SpaceDaily Monthly Supporter
$5 Billed Monthly


paypal only

Comment using your Disqus, Facebook, Google or Twitter login.

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

NANO TECH
NASA Moves Up Critical Crew Safety Launch Abort Test

NanoRacks launches Full External Cygnus Deployer on OA-8 to ISS

Robotic arm reaches out and grapples Cygnus

Colossal SoftBank fund could shake up tech world

NANO TECH
Orbital ATK launches eighth cargo mission to space

The state of commercial spaceports in 2017

Vega launches Earth observation satellite for Morocco

Orbital ATK Successfully Tests First Motor Case for Next Generation Launch Vehicle

NANO TECH
Mars 2020 Mission performs first supersonic parachute test

New partnership on Mars drone applications research

Powering up NASA's human reach for the Red Planet

NASA Opens $2 Million Third Phase of 3D-Printed Habitat Competition

NANO TECH
China's reusable spacecraft to be launched in 2020

Space will see Communist loyalty: Chinese astronaut

China launches three satellites

Mars probe to carry 13 types of payload on 2020 mission

NANO TECH
Astronaut meets volcano

European Space Week starts in Estonia

New Chinese sat comms company awaits approval

Myanmar to launch own satellite system-2 in 2019: vice president

NANO TECH
Leonardo tapped by British Royal Air Force for radar testing equipment

A new way to mix oil and water

Building better silk

Plasma from lasers can shed light on cosmic rays, solar eruptions

NANO TECH
Astronomers See Moving Shadows Around Planet-Forming Star

NASA plans mission to study why planets lose their atmospheres

Scientists find potential 'missing link' in chemistry that led to life on earth

18-Month Twinkle in a Forming Star Suggests a Very Young Planet

NANO TECH
Jupiter's Stunning Southern Hemisphere

Watching Jupiter's multiple pulsating X-ray Aurora

Help Nickname New Horizons' Next Flyby Target

Juno Aces 8th Science Pass of Jupiter, Names New Project Manager




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






The content herein, unless otherwise known to be public domain, are Copyright 1995-2017 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news 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. All articles labeled "by Staff Writers" include reports supplied to Space Media Network by industry news wires, PR agencies, corporate press officers and the like. Such articles are individually curated and edited by Space Media Network staff on the basis of the report's information value to our industry and professional readership. 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