Subscribe free to our newsletters via your
. 24/7 Space News .

Vortex pinning could lead to superconducting breakthroughs
by Louise Lerner for ANL News
Argonne IL (SPX) Feb 25, 2013

This mosaic represents the distribution of superconductivity around holes (white) in a thin sheet of superconducting film. Green indicates strong superconductivity. Further away from the holes, the superconductivity decreases (yellow, red and finally black, where the material is densely populated with vortices that interfere with superconductivity.

A team of researchers from Russia, Spain, Belgium, the U.K. and the U.S. Department of Energy's (DOE) Argonne National Laboratory announced findings last week that may represent a breakthrough in applications of superconductivity.

The team discovered a way to efficiently stabilize tiny magnetic vortices that interfere with superconductivity-a problem that has plagued scientists trying to engineer real-world applications for decades. The discovery could remove one of the most significant roadblocks to advances in superconductor technology.

Superconductors are extremely useful materials, given that modern society involves moving a lot of electricity around. Each time we do it, whether it be along the cord from the outlet to your lamp or in the millions of miles of power lines strung across the country, we lose a little bit of electricity. That effect is due to resistance in the wires we currently use to transport electricity. Even a pretty good conductor, like copper wire, loses some electricity due to resistance.

But in an ideal superconductor, no electricity is ever lost. If you set up a loop of perfect superconducting wire and added some current, it would circle that loop forever. Superconductors are the secret behind MRI machines, Maglev trains and improved cell phone reception.

The problem is that superconductors have to be cooled to do their thing. Even the "high-temperature" superconductors already discovered have to be chilled to -280 Fahrenheit. That creates a lot of engineering and logistical problems.

In the long run, scientists are hoping to develop superconducting materials that would operate closer to room temperature. That would be a major achievement-though it is generally still thought to be a long way off.

In the meantime, there remain key problems of superconductivity that need to be solved even in the low-temperature environment.

One such major problem is posed by magnetic fields. When magnetic fields reach a certain strength, they cause a superconductor to lose its superconductivity. But there is a type of superconductor-known as "Type II"-which is better at surviving in relatively high magnetic fields.

In these superconductors, magnetic fields create tiny whirlpools or "vortices." Superconducting current continues to travel around these vortices to a point, but eventually, as the magnetic field strengthens, the vortices begin to move about and interfere with the material's superconductivity, introducing resistance.

"These vortices dissipate the energy when moving under applied currents and bury all hopes for a technological revolution-unless we find ways to efficiently pin them," said Argonne Distinguished Fellow Valerii Vinokur, who co-authored the study.

Scientists have spent a lot of time and effort over the past few decades trying to immobilize these vortices, but until now, the results have been mixed. They found ways to pin down the vortices, but these only worked in a restricted range of low temperatures and magnetic fields.

Vinokur and his colleagues, however, discovered a surprise. They began with very thin superconducting wires-just 50 nanometers in diameter. (A stack of 2,000 of these wires would equal the height of a sheet of paper.) These thin wires can accommodate only one row of vortices. When they applied a high magnetic field, the vortices crowded together in long clusters and stopped moving. Increasing the magnetic field restored the material's superconductivity, instead of destroying it.

Next, the team carved superconducting film into an array of holes so that only a few vortices could squeeze between the holes, where they stayed, unable to interfere with current.

The resistance of the superconductor dropped dramatically-at temperatures and magnetic fields where no one has been able to pin vortices before. "The results were quite striking," Vinokur said.

The team has only experimented with low-temperature superconductors so far, Vinokur said, "but there is no reason why the approach we used should be restricted to just low-temperature superconductors."

The paper, "Magnetic field-induced dissipation-free state in superconducting nanostructures," is published this week in Nature Communications. Vinokur and Tatyana Baturina, a visiting scientist at Argonne, authored the paper, along with researchers from the A.B. Rzhanov Institute of Semiconductor Physics in Russia, the Autonomous University of Madrid and the University of Zaragoza in Spain, the University of Bristol in the U.K. and the Interuniversity Microelectronics Centre in Belgium.


Related Links
Argonne National Laboratory
Powering The World in the 21st Century at

Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks DiggDigg RedditReddit GoogleGoogle

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

Dopants dramatically alter electronic structure of superconductor
Upton, NY (SPX) Feb 22, 2013
Over the last quarter century, scientists have discovered a handful of materials that can be converted from magnetic insulators or metals into "superconductors" able to carry electrical current with no energy loss-an enormously promising idea for new types of zero-resistance electronics and energy-storage and transmission systems. At present, a key step to achieving superconductivity (in a ... read more

Water On The Moon: It's Been There All Along

Building a lunar base with 3D printing

US, Europe team up for moon fly-by

Russia to Launch Lunar Mission in 2015

NASA Rover Confirms First Drilled Mars Rock Sample

India plans mission to Mars in 2013

Rover finds gray rock beneath Red Planet's surface

Bleach could hamper Mars life search

Supersonic skydiver's records confirmed

Kennedy Engineers Designing Plant Habitat For ISS

NASA plant study headed to space station

NASA Spinoff 2012 Features New Space Tech Bettering Your Life Today

Welcome Aboard Shenzhou 10

Reshuffle for Tiangong

China to launch 20 spacecrafts in 2013

Mr Xi in Space

NASA briefly loses contact with space station

Temporary Comm Loss Interrupts Crew's Day

Low-Gravity Flights Will Aid ISS Fluids and Combustion Experiments

Progress docks with ISS

Countdown begins for Indo-French satellite launch

NASA Seeks University Participants for Summer Rocket Workshop

Another Sea Launch Failure

ILS Concludes Yamal 402 Proton Launch Investigation

NASA's Kepler Mission Discovers Tiny Planet System

Kepler helps astronomers find tiny exo planet

Searching for a Pale Blue SPHERE in the Universe

Earth-like planets are right next door

A Semiconductor 'Nano-Shish-Kebabs' With 3-D Potential

That's the way the droplets adhere

Acoustic-assisted magnetic information storage

DARPA Seeks to Defuse the Threat of Ionizing Radiation

The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA Portal 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. 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