Nanotechnology Now





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

Transition from 3 to 2 dimensions increases conduction, MIPT scientists discover July 6th, 2015

A Stretchy Mesh Heater for Sore Muscles July 6th, 2015

BBC World Service to broadcast Forum discussion on graphene July 6th, 2015

Production of Zirconium Carbide Nanoparticles at Low Temperature without Thermal Operations July 5th, 2015

Laboratories

Influential Interfaces Lead to Advances in Organic Spintronics July 1st, 2015

NIST ‘How-To’ Website Documents Procedures for Nano-EHS Research and Testing July 1st, 2015

Ultra-stable JILA microscopy technique tracks tiny objects for hours July 1st, 2015

X-rays and electrons join forces to map catalytic reactions in real-time: New technique combines electron microscopy and synchrotron X-rays to track chemical reactions under real operating conditions June 29th, 2015

Govt.-Legislation/Regulation/Funding/Policy

New technology using silver may hold key to electronics advances July 2nd, 2015

NIST Group Maps Distribution of Carbon Nanotubes in Composite Materials July 2nd, 2015

NIST ‘How-To’ Website Documents Procedures for Nano-EHS Research and Testing July 1st, 2015

Ultra-stable JILA microscopy technique tracks tiny objects for hours July 1st, 2015

Quantum Computing

The quantum middle man July 2nd, 2015

Freezing single atoms to absolute zero with microwaves brings quantum technology closer: Atoms frozen to absolute zero using microwaves July 2nd, 2015

Producing spin-entangled electrons July 2nd, 2015

Opening a new route to photonics Berkeley lab researchers find way to control light in densely packed nanowaveguides June 27th, 2015

Sensors

New Biosensor Produced in Iran to Detect Effective Drugs in Cancer Treatment July 4th, 2015

Groundbreaking research to help control liquids at micro and nano scales July 3rd, 2015

New micro-supercapacitor structure inspired by the intricate design of leaves: A team of scientists in Korea has devised a new method for making a graphene film for supercapacitors July 2nd, 2015

Carnegie Mellon chemists characterize 3-D macroporous hydrogels: Methods will allow researchers to develop new 'smart' materials June 30th, 2015

Discoveries

Transition from 3 to 2 dimensions increases conduction, MIPT scientists discover July 6th, 2015

A Stretchy Mesh Heater for Sore Muscles July 6th, 2015

Production of Zirconium Carbide Nanoparticles at Low Temperature without Thermal Operations July 5th, 2015

A 'movie' of ultrafast rotating molecules at a hundred billion per second: A quantum wave-like nature was successfully observed in rotating nitrogen molecules July 4th, 2015

Announcements

Transition from 3 to 2 dimensions increases conduction, MIPT scientists discover July 6th, 2015

A Stretchy Mesh Heater for Sore Muscles July 6th, 2015

BBC World Service to broadcast Forum discussion on graphene July 6th, 2015

Production of Zirconium Carbide Nanoparticles at Low Temperature without Thermal Operations July 5th, 2015

Tools

A 'movie' of ultrafast rotating molecules at a hundred billion per second: A quantum wave-like nature was successfully observed in rotating nitrogen molecules July 4th, 2015

Clues to inner atomic life from subtle light-emission shifts: Hyperfine structure of light absorption by short-lived cadmium atom isotopes reveals characteristics of the nucleus that matter for high precision detection methods July 3rd, 2015

Nanometrics to Announce Second Quarter Financial Results on July 23, 2015 July 2nd, 2015

Ultra-stable JILA microscopy technique tracks tiny objects for hours July 1st, 2015

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