Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Researchers propose breakthrough devices to control the motion of magnetic fields

06.11.2002


Researchers from the University of Michigan and RIKEN, a research institute in Japan, say the biological motors that nature uses for intracellular transport and other biological functions inspired them to create a whole new class of micro-devices for controlling magnetic flux quanta in superconductors that could lead to the development of a new generation of medical diagnostic tools.

As integrated circuits become smaller and smaller, it becomes increasingly difficult to create the many "guiding channels" that act like wires to move electrons around the circuit components.

This difficulty in wiring nano-circuits must be overcome if researchers are to continue developing the microscopic machines and sensors that represent the wave of the future in nanotechnology. A similar problem exists for researchers developing better magnetic imaging tools for medical diagnostics. Here the goal is to control the motion of magnetic field lines within the superconducting material, so that their motion does not produce noise that degrades the performance of the diagnostic device. A new approach and several novel devices described in a recent article in Nature Materials offer hope that the noise challenge has been overcome.



In the November issue of Nature Materials, researchers Franco Nori of the Center for Theoretical Physics, Physics Department, Applied Physics Program, and the Center for the Study of Complex Systems at the University of Michigan and the Frontier Research System of the Institute of Physical and Chemical Research (RIKEN) in Tokyo, and Sergey Savel’ev of RIKEN have described a number of new ways to control the motion of flux quanta.

Magnetic fields penetrate superconducting materials via lattices of quantized magnetic flux, called vortices because electrons whirl around them without dissipating energy. Electrical currents, externally applied to superconducting devices, induce the motion of these magnetic flux quanta. This vortex motion produces noise that degrades the device performance in practical applications, such as the sensitive measuring of the magnetic fields produced by the brain. Therefore, the precise control of the motion of these vortices is of central importance for applications involving superconducting materials.

By controlling the motion of quanta inside superconducting materials, the new devices allow the design of micro-machines such as "pumps," "diodes" and "lenses" of magnetic flux quanta to create specific magnetic profiles within a given sample or device. This would give designers the ability to remove unwanted flux trapped inside superconducting devices and enable researchers to increase the magnetic field in designated target regions inside materials, which would "magnetically focus" nearby magnetic particles.

Inspired by the design of biological "motors" that use sawtooth-shaped spatially-asymmetric structures (one slope of the sawtooth-shaped structure has a steep slope, and the other one a mild slope) to move small objects, Nori and Savel’ev propose using time-asymmetric forces to achieve a similar sawtooth pattern. By repeatedly pushing slowly in one direction, and fast in the opposite direction, they force magnetic flux quanta to move from one point to another inside materials. Their proposed solid-state devices could be used in specific technological applications, including the removal of unwanted fluctuating vortices inside the most sensitive magnetic field sensors used for medical imaging, and to sculpt the magnetic flux profile inside superconducting materials as needed for specific applications.

Moreover, these devices achieve control without having to resort to the umbersome electron-beam lithography or irradiation techniques that are now used to pattern the host material. "[The researchers’] groundbreaking idea is to apply a current or magnetic field to the superconductor that is asymmetric in time, rather than space," said G. D’Anna of the Ecole Polytechnique Fédérale de Lausanne in Switzerland, writing in the same issue of Nature Materials. "This remarkable proposal makes it possible to create asymmetric flux motion, which should inspire experimentalists to build a new generation of superconducting devices for controlling magnetic flux quanta."

One of the devices, for example, acts like a convex or concave lens, allowing the creation of a "changeable magnetic landscape" inside the superconducting material (see the two schematic diagrams of "magnetic lenses"). But the authors also stress that their idea has a broader scope. "These are a whole new class of micro-devices," Nori says. "The point is that in a complex system, a time-asymmetric external force applied to one set or species of moveable objects can precisely control the dynamics of another subset, even without the external force directly interacting with the latter. This allows novel ways of indirect manipulation and control of the motion of one species of particles by using another type that interacts with it. For instance, small particles with different electric charges or different magnetic moments could be manipulated via this technique."


The manuscript is available from http://www.nature.com/cgi-taf/DynaPage.taf?file=/nmat/journal/v1/n3/abs/nmat746.html&dynoptions=doi1036515051.

For the full text, contact author: Prof. F. Nori at nori@umich.edu.

Contact: Judy Steeh
Phone: 734-647-3099
E-mail: jsteeh@umich.edu


The University of Michigan
News Service
412 Maynard
Ann Arbor, MI 48109-1399

Judy Steeh | EurekAlert!
Further information:
http://www.physics.lsa.umich.edu/nea/
http://www.riken.go.jp/engn/r-world/research/lab/frontier/quantum/digital/index.html
http://www.umich.edu/~newsinfo

More articles from Physics and Astronomy:

nachricht Quantum optics allows us to abandon expensive lasers in spectroscopy
22.11.2017 | Lomonosov Moscow State University

nachricht Nano-watch has steady hands
22.11.2017 | University of Vienna

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Nanoparticles help with malaria diagnosis – new rapid test in development

The WHO reports an estimated 429,000 malaria deaths each year. The disease mostly affects tropical and subtropical regions and in particular the African continent. The Fraunhofer Institute for Silicate Research ISC teamed up with the Fraunhofer Institute for Molecular Biology and Applied Ecology IME and the Institute of Tropical Medicine at the University of Tübingen for a new test method to detect malaria parasites in blood. The idea of the research project “NanoFRET” is to develop a highly sensitive and reliable rapid diagnostic test so that patient treatment can begin as early as possible.

Malaria is caused by parasites transmitted by mosquito bite. The most dangerous form of malaria is malaria tropica. Left untreated, it is fatal in most cases....

Im Focus: A “cosmic snake” reveals the structure of remote galaxies

The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.

Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...

Im Focus: Visual intelligence is not the same as IQ

Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.

That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...

Im Focus: Novel Nano-CT device creates high-resolution 3D-X-rays of tiny velvet worm legs

Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.

During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....

Im Focus: Researchers Develop Data Bus for Quantum Computer

The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.

Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Ecology Across Borders: International conference brings together 1,500 ecologists

15.11.2017 | Event News

Road into laboratory: Users discuss biaxial fatigue-testing for car and truck wheel

15.11.2017 | Event News

#Berlin5GWeek: The right network for Industry 4.0

30.10.2017 | Event News

 
Latest News

Corporate coworking as a driver of innovation

22.11.2017 | Business and Finance

PPPL scientists deliver new high-resolution diagnostic to national laser facility

22.11.2017 | Physics and Astronomy

Quantum optics allows us to abandon expensive lasers in spectroscopy

22.11.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>