Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button

Home > Press > Superconducting nanowires show ability to measure magnetic fields

Abstract:
Nanodevices could be used to measure magnetic fields and map regions of superconductivity

Superconducting nanowires show ability to measure magnetic fields

Champaign, IL | June 16, 2005

By using DNA molecules as scaffolds, scientists have created superconducting nanodevices that demonstrate a new type of quantum interference and could be used to measure magnetic fields and map regions of superconductivity.

Researchers at the University of Illinois at Urbana-Champaign have fabricated and studied nanostructures consisting of pairs of suspended superconducting wires as tiny as 3 to 4 molecular diameters (typically 5 to 15 nanometers) in width. The team consisted of physics professors Alexey Bezryadin and Paul Goldbart, and graduate students David Hopkins and David Pekker. Their work is described in the June 17 issue of the journal Science.

“Our measurements on these two-nanowire devices revealed a strange class of periodic oscillations in resistance with applied magnetic field,” Bezryadin said. “Through experimentation and theory, we found both an explanation for this odd behavior and a way to put it to work.”

To make their nanodevices, the researchers began by placing molecules of DNA across a narrow trench (about 100 nanometers wide) etched in a silicon wafer. The molecules and trench banks were then coated with a thin film of superconducting material (molybdenum-germanium). The result was a device containing a pair of homogeneous, superconducting nanowires with extremely fine features.

“In the absence of a magnetic field, these ultra-narrow wires exhibited a nonzero resistance over a broad temperature range,” Bezryadin said. “At temperatures where thicker wires would already be superconducting, these DNA-templated wires remained resistive.”

Tuning the strength of a magnetic field applied to the device, however, caused highly pronounced and periodic oscillations in resistance, at any temperature in the transition region.

“The applied magnetic field causes a small current to flow along the trench banks, and this current then causes a large change in resistance,” Goldbart said. “The strength of the current is controlled only by the magnetic field and the width of the banks supporting the wires.”

The resulting periodic oscillation is a reflection of the wave nature of matter that goes to the very heart of quantum mechanics, Goldbart said. “Unlike ordinary matter, the electrons in these wires are behaving as though they are one quantum mechanical object in one great quantum mechanical wave function.”

Metallic nanodevices based on DNA scaffolds could be used in applications such as local magnetometry and the imaging of phase profiles created by supercurrents – in essence a superconducting phase gradiometer, the researchers report.

“By taking advantage of DNA self-assembly processes, complex scaffolds could be created for electronic devices with features having molecular-scale dimensions,” Bezryadin said.

In related work, to appear in the August issue of the journal Nanotechnology (published online in May), Bezryadin and undergraduate student Mikas Remeika improved the nanofabrication process by using a focused electron beam to locally alter the shape and structure of metallized nanowires.

Performed in a transmission electron microscope, electron-beam sculpting and crystallization can modify small segments of the nanowires, with a spatial resolution of approximately 3 nanometers, Bezryadin said. The technique could be used to fabricate novel electronic nanodevices, such as single-electron transistors, with dimensions less than 10 nanometers.

Funding came from the National Science Foundation, the Alfred P. Sloan Foundation and the U.S. Department of Energy.

Editor’s note: To reach Alexey Bezryadin, call 217-333-9580; e-mail: bezryadi@uiuc.edu.

To reach Paul Goldbart, call 217-333-1195; e-mail: goldbart@uiuc.edu.

####

Contact:
James E. Kloeppel
Physical Sciences Editor
217-244-1073
kloeppel@uiuc.edu

Copyright © University of Illinois at Urbana-Champaign

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

Possible Futures

Atomic imperfections move quantum communication network closer to reality June 25th, 2017

Research accelerates quest for quicker, longer-lasting electronics: UC Riverside-led research makes topological insulators magnetic well above room temperatures June 25th, 2017

U.S. Air Force Research Lab Taps IBM to Build Brain-Inspired AI Supercomputing System: Equal to 64 million neurons, new neurosynaptic supercomputing system will power complex AI tasks at unprecedented speed and energy efficiency June 23rd, 2017

Rice U. chemists create 3-D printed graphene foam June 22nd, 2017

Self Assembly

Oddball enzyme provides easy path to synthetic biomaterials May 17th, 2017

Nanotubes that build themselves April 14th, 2017

Nanocages for gold particles: what is happening inside? March 16th, 2017

Most Complex Nanoparticle Crystal Ever Made by Design: Possible applications include controlling light, capturing pollutants, delivering therapeutics March 2nd, 2017

Announcements

Atomic imperfections move quantum communication network closer to reality June 25th, 2017

Research accelerates quest for quicker, longer-lasting electronics: UC Riverside-led research makes topological insulators magnetic well above room temperatures June 25th, 2017

U.S. Air Force Research Lab Taps IBM to Build Brain-Inspired AI Supercomputing System: Equal to 64 million neurons, new neurosynaptic supercomputing system will power complex AI tasks at unprecedented speed and energy efficiency June 23rd, 2017

Rice U. chemists create 3-D printed graphene foam June 22nd, 2017

Tools

Researchers developed nanoparticle based contrast agent for dual modal imaging of cancer June 21st, 2017

Oxford Instruments congratulates Lancaster University for inaugurating the IsoLab, built for studying quantum systems June 20th, 2017

Changing the color of laser light on the femtosecond time scale: How BiCoO3 achieves second harmonic generation June 14th, 2017

Leti Announces Two New Tools for Improving Transportation Comfort, Safety and Efficiency: Wearable Device Measures Stress Responses for Travelers, Pilots and Truck Drivers, While Smartphone App Provides Transit Agencies Broad Data on Transport Modes June 13th, 2017

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