Nanotechnology Now

Our NanoNews Digest Sponsors


Heifer International

Wikipedia Affiliate Button


DHgate

Home > Press > Key Ingredient: Change in Material Boosts Prospects of Ultrafast Single-photon Detector

Colorized micrograph of an ultrafast single-photon detector made of superconducting nanowires. NIST researchers use electron beam lithography to pattern the nanowires (vertical lines) on a thin film of tungsten-silicon alloy, which produces more reliable signals than the niobium nitride material used previously.
Credit: Baek/NIST
Colorized micrograph of an ultrafast single-photon detector made of superconducting nanowires. NIST researchers use electron beam lithography to pattern the nanowires (vertical lines) on a thin film of tungsten-silicon alloy, which produces more reliable signals than the niobium nitride material used previously.

Credit: Baek/NIST

Abstract:
By swapping one superconducting material for another, researchers at the National Institute of Standards and Technology (NIST) have found a practical way to boost the efficiency of the world's fastest single-photon detector, while also extending light sensitivity to longer wavelengths. The new tungsten-silicon alloy could make the ultrafast detectors more practical for use in quantum communications and computing systems, experiments testing the nature of reality, and emerging applications such as remote sensing.

Key Ingredient: Change in Material Boosts Prospects of Ultrafast Single-photon Detector

Boulder, CO | Posted on July 2nd, 2011

The detector, made of superconducting nanowires, is one of several sensor designs developed or used at NIST to register individual photons (particles of light). The original nanowire detector, invented in Russia, uses wires made of niobium nitride and has a detection or quantum efficiency—ability to generate an electrical signal for each arriving photon—of less than 10 percent in its simplest, most compact model. NIST's tungsten-silicon alloy version has an efficiency of 19 to 40 percent over a broad wavelength range of 1280 to 1650 nanometers, including bands used in telecommunications.* The limitations are due mainly to imperfect photon absorption, suggesting that, with further design improvements, detector efficiency could approach 100 percent reliably, researchers say.

Superconducting nanowire detectors have many advantages. They are very fast, able to count nearly a billion photons per second, and they operate over a large range of wavelengths, have low dark (false) counts, and produce strong signals, especially at telecom wavelengths. The detectors produce a signal when a photon breaks apart some of the electron pairs that carry current in the superconducting state, where the material has zero resistance. If the nanowires are narrow enough and the DC current across the device is very close to the transition between ordinary and super conductance, a resistive band temporarily forms across each wire, resulting in a measurable voltage pulse.

Niobium nitride is difficult to make into nanowires that are narrow, long, and sensitive enough to work well. NIST researchers selected the tungsten-silicon alloy mainly because it has higher energy sensitivity, resulting in more reliable signals. A photon breaks more electron pairs in the tungsten-silicon alloy than in niobium nitride. The tungsten alloy also has a more uniform and less granular internal structure, making the nanowires more reliably sensitive throughout. As a result of the higher energy sensitivity, tungsten-silicon nanowires can have larger dimensions (150 nanometers wide versus 100 nanometers or less for niobium nitride), which enlarges the detectors' functional areas to more easily capture all photons.

The NIST team now hopes to raise the efficiency of tungsten alloy detectors by embedding them in optical cavities, which trap light for extremely high absorption. High efficiency may enable the use of nanowire detectors in demanding applications such as linear optical quantum computing, which encodes information in single photons. An equally intriguing application may be an experiment to test quantum mechanics—the so-called "loophole-free Bell test." This test of what Einstein called "spooky action at a distance" depends critically on having a nearly 100-percent efficient photon detector. Tungsten-silicon detectors also are sensitive to longer wavelengths of light, in the mid-infrared range, which could be useful for applications such as laser-based remote sensing of trace gases.

* B. Baek, A.E. Lita, V. Verma and S.W. Nam. Superconducting a-WxSi1-x nanowire single-photon detector with saturated internal quantum efficiency from visible to 1850 nm. Applied Physics Letters 98, 251105. Published online June 21, 2011.

####

About National Institute of Standards and Technology (NIST)
The National Institute of Standards and Technology (NIST) is an agency of the U.S. Department of Commerce.

For more information, please click here

Contacts:
Laura Ost
303-497-4880

Copyright © NIST

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related News Press

News and information

Superheroes are real: Ultrasensitive nonlinear metamaterials for data transfer June 25th, 2016

Russian physicists create a high-precision 'quantum ruler': Physicists have devised a method for creating a special quantum entangled state June 25th, 2016

Nanoscientists develop the 'ultimate discovery tool': Rapid discovery power is similar to what gene chips offer biology June 25th, 2016

Ultrathin, flat lens resolves chirality and color: Multifunctional lens could replace bulky, expensive machines June 25th, 2016

Laboratories

Titan shines light on high-temperature superconductor pathway: Simulation demonstrates how superconductivity arises in cuprates' pseudogap phase June 22nd, 2016

Discovery of gold nanocluster 'double' hints at other shape-changing particles: New analysis approach brings two unique atomic structures into focus June 19th, 2016

Efficient hydrogen production made easy: Sticking electrons to a semiconductor with hydrazine creates an electrocatalyst June 17th, 2016

Discovery of gold nanocluster 'double' hints at other shape changing particles: New analysis approach brings two unique atomic structures into focus June 15th, 2016

Govt.-Legislation/Regulation/Funding/Policy

Nanoscientists develop the 'ultimate discovery tool': Rapid discovery power is similar to what gene chips offer biology June 25th, 2016

Ultrathin, flat lens resolves chirality and color: Multifunctional lens could replace bulky, expensive machines June 25th, 2016

Particle zoo in a quantum computer: First experimental quantum simulation of particle physics phenomena June 23rd, 2016

Titan shines light on high-temperature superconductor pathway: Simulation demonstrates how superconductivity arises in cuprates' pseudogap phase June 22nd, 2016

Quantum Computing

Particle zoo in a quantum computer: First experimental quantum simulation of particle physics phenomena June 23rd, 2016

CWRU physicists deploy magnetic vortex to control electron spin: Potential technology for quantum computing, keener sensors June 21st, 2016

Researchers refine method for detecting quantum entanglement June 18th, 2016

UChicago physicists first to see behavior of quantum materials in curved space: Feat probes light-matter interplay, phenomena of potential technological interest June 16th, 2016

Sensors

Researchers discover new chemical sensing technique: Technique allows sharper detail -- and more information -- with near infrared light June 24th, 2016

Artificial synapse rivals biological ones in energy consumption June 21st, 2016

A new form of hybrid photodetectors with quantum dots and graphene June 19th, 2016

Drum beats from a one atom thick graphite membrane June 15th, 2016

Discoveries

Superheroes are real: Ultrasensitive nonlinear metamaterials for data transfer June 25th, 2016

Russian physicists create a high-precision 'quantum ruler': Physicists have devised a method for creating a special quantum entangled state June 25th, 2016

Nanoscientists develop the 'ultimate discovery tool': Rapid discovery power is similar to what gene chips offer biology June 25th, 2016

Ultrathin, flat lens resolves chirality and color: Multifunctional lens could replace bulky, expensive machines June 25th, 2016

Announcements

Superheroes are real: Ultrasensitive nonlinear metamaterials for data transfer June 25th, 2016

Russian physicists create a high-precision 'quantum ruler': Physicists have devised a method for creating a special quantum entangled state June 25th, 2016

Nanoscientists develop the 'ultimate discovery tool': Rapid discovery power is similar to what gene chips offer biology June 25th, 2016

Ultrathin, flat lens resolves chirality and color: Multifunctional lens could replace bulky, expensive machines June 25th, 2016

Tools

Nanoscientists develop the 'ultimate discovery tool': Rapid discovery power is similar to what gene chips offer biology June 25th, 2016

Ultrathin, flat lens resolves chirality and color: Multifunctional lens could replace bulky, expensive machines June 25th, 2016

Researchers discover new chemical sensing technique: Technique allows sharper detail -- and more information -- with near infrared light June 24th, 2016

Coexistence of superconductivity and charge density waves observed June 23rd, 2016

NanoNews-Digest
The latest news from around the world, FREE




  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project







Car Brands
Buy website traffic