 |
|
Superconducting nanowires show ability to measure magnetic fields
June 16, 2005By 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.
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.
University of Illinois at Urbana-Champaign
Superconducting Current Events and Superconducting News RSSPhysicists at UC Santa Barbara make discovery in quantum mechanics
Physicists at UC Santa Barbara have made an important advance in quantum mechanics using a superconducting electrical circuit. The finding is reported in this week's issue of the journal Nature.
American-Made SRF Cavity Makes the Grade
The U.S. Department of Energy's (DOE's) Thomas Jefferson National Accelerator Facility marked a step forward in the field of advanced particle accelerator technology with the successful test of the first U.S.-built superconducting radiofrequency (SRF) niobium cavity to meet the exacting specifications of the proposed International Linear Collider (ILC).
Scientists detect 'fingerprint' of high-temp superconductivity above transition temperature
A team of U.S. and Japanese scientists has shown for the first time that the spectroscopic "fingerprint" of high-temperature superconductivity remains intact well above the super chilly temperatures at which these materials carry current with no resistance.
Up-scale: Frequency converter enables ultra-high sensitivity infrared spectrometry
In what may prove to be a major development for scientists in fields ranging from forensics to quantum communications, researchers at the National Institute of Standards and Technology (NIST) have developed a new, highly sensitive, low-cost technique for measuring light in the near-infrared range.
Experiments at UCSB push quantum mechanics to higher levels
Scientists at UC Santa Barbara have devised a new type of superconducting circuit that behaves quantum mechanically -- but has up to five levels of energy instead of the usual two. The findings are published in the August 7 issue of Science.
On the path to metallic hydrogen
Hydrogen, the most common element in the universe, is normally an insulating gas, but at high pressures it may turn into a superconductor.
Superconductivity: Which one of these is not like the other?
Superconductivity appears to rely on very different mechanisms in two varieties of iron-based superconductors.
Scientists create first working model of a 2-qubit electronic quantum processor
A team led by Yale University researchers has successfully implemented simple algorithms using a quantum processor based on microwave solid-state technology--similar to that found in computers and cell phones.
Scientists create first electronic quantum processor
A team led by Yale University researchers has created the first rudimentary solid-state quantum processor, taking another step toward the ultimate dream of building a quantum computer.
Mechanics: Ordinary meets quantum
At the quantum level, the atoms that make up matter and the photons that make up light behave in a number of seemingly bizarre ways.
More Superconducting Current Events and Superconducting News Articles
 |
Case Studies in Superconducting Magnets: Design and Operational Issues by Yukikazu Iwasa (Author) The 2nd edition emphasizes two areas not emphasized in the 1st edition: 1) high-temperature superconductor (HTS) magnets; 2) NMR (nuclear magnetic resonance) and MRI (magnetic resonance imaging) magnets. Despite nearly 40 years of R and D on superconducting magnet technology, most areas, notably fusion and electric power applications, are still in the R and D stage. One exception is in the area of NMR and MRI. NMR magnets are very popular among chemists, biologists, genome scientists, and most of all, by drug manufacturers for drug discovery and development. MRI and NMR magnets have become the most successful application of superconducting magnet technology and this trend should continue. The 2nd edition will have new materials never treated formally in any other book... |
 |
A superconducting magnet is lowered into the particle collider Photographic Poster Print by Mark Thiessen, 42x56 by Art.com Art.com is the world's largest retailer of art prints, posters, photographs, and framed artwork. With our huge selection of over 400,000 prints, you'll easily find the perfect piece for your home, office, or classroom. Our art is printed on quality paper. When you order framed artwork, the piece is built by our team of in-house professionals. Visit our Amazon store today at www.amazon.com/artdotcom to find Special Offers and search for products based on 'Artist Name' and 'Subject Categories' such as Movie, Music, Vintage, TV, Children, Travel, Kitchen, Museum Art, Animals, Floral, Motivational, and Sports. Art.com is dedicated to providing you with high quality products and service by offering you 100% satisfaction guaranteed. We ship internationally to over 80 countries. Decorate your... |
 |
Electrically Small, Superdirective, and Superconducting Antennas by R. C. Hansen (Author) A seminal reference to electrically small antennas for today's wireless and Wi-Fi world This book is dedicated to the challenges posed by electrically small antennas and their solutions. Electrically small antennas have characteristics that limit performance: low radiation resistance, high reactance, low efficiency, narrow bandwidth, and increased loss in the matching network. Most of these limitations are shared by two other classes of antennas: superdirective and superconducting antennas. All three classes of antennas are thoroughly treated in three interrelated parts: * Part One, Electrically Small Antennas, begins with a discussion of the fundamental limitations of bandwidth and matching, then provides detailed design information on loaded whips and... |
 |
Superconducting Technology: 10 Case Studies by K. Fossheim (Editor) |
|
|
A superconducting magnet is lowered into the particle collider Photographic Poster Print by Mark Thiessen, 12x16 by Art.com Art.com is the world's largest retailer of art prints, posters, photographs, and framed artwork. With our huge selection of over 400,000 prints, you'll easily find the perfect piece for your home, office, or classroom. Our art is printed on quality paper. When you order framed artwork, the piece is built by our team of in-house professionals. Visit our Amazon store today at www.amazon.com/artdotcom to find Special Offers and search for products based on 'Artist Name' and 'Subject Categories' such as Movie, Music, Vintage, TV, Children, Travel, Kitchen, Museum Art, Animals, Floral, Motivational, and Sports. Art.com is dedicated to providing you with high quality products and service by offering you 100% satisfaction guaranteed. We ship internationally to over 80 countries. Decorate your... |
 |
Handbook of Superconducting Materials by David A. Cardwell (Editor), David S. Ginley (Editor) Comprehensive guide to the techniques used to fabricate, characterize, and measure superconducting materials. Two volume set includes Volume 1: Superconductivity, Materials and Processes; and Volume 2: Characterization, Applications and Cryogenics. For researchers and graduate students. |
|
Superconducting Accelerator Magnets by K. H. Mess (Author), P. Schmuser (Author), S. Wolff (Author) The main topic of the book are the superconducting dipole and quadrupole magnets needed in high-energy accelerators and storage rings for protons, antiprotons or heavy ions. The basic principles of low-temperature superconductivity are outlined with special emphasis on the effects which are relevant for accelerator magnets. Properties and fabrication methods of practical superconductors are described. Analytical methods for field calculation and multipole expansion are presented for coils without and with iron yoke. The effect of yoke saturation and geometric distortions on field quality is studied. Persistent magnetization currents in the superconductor and eddy currents the copper part of the cable are analyzed in detail and their influence on field quality and magnet... | |
|
|
A superconducting magnet is lowered into the particle collider Photographic Poster Print by Mark Thiessen, 30x40 by Art.com Art.com is the world's largest retailer of art prints, posters, photographs, and framed artwork. With our huge selection of over 400,000 prints, you'll easily find the perfect piece for your home, office, or classroom. Our art is printed on quality paper. When you order framed artwork, the piece is built by our team of in-house professionals. Visit our Amazon store today at www.amazon.com/artdotcom to find Special Offers and search for products based on 'Artist Name' and 'Subject Categories' such as Movie, Music, Vintage, TV, Children, Travel, Kitchen, Museum Art, Animals, Floral, Motivational, and Sports. Art.com is dedicated to providing you with high quality products and service by offering you 100% satisfaction guaranteed. We ship internationally to over 80 countries. Decorate your... |
 |
Superconducting Magnets (Monographs on Cryogenics, 2) by Martin N. Wilson (Author) Now back in print, this classic work provides a complete theoretical basis for the engineering design of superconducting magnet systems, from the small instrument magnets used as everyday research tools to the very large magnet systems used to work on thermonuclear fusion and magnetohydrodynamic power generation. |
 |
High Field Superconducting Magnets (Oxford Science Publications) by Fred M. Asner (Author) Superconducting devices are improving at a tremendous pace. This book provides a modern, up-to-date reference on both the physics and the technology of superconducting magnets. It is unique in combining the theoretical aspects of superconductivity, electromagnetic field theory, and the thermodynamics of helium cooling with the technological details for producing and engineering high performance superconducting materials. |
| © 2009 BrightSurf.com |