Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Researchers propose breakthrough devices to control the motion of magnetic fields


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

For the full text, contact author: Prof. F. Nori at

Contact: Judy Steeh
Phone: 734-647-3099

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

Judy Steeh | EurekAlert!
Further information:

More articles from Physics and Astronomy:

nachricht Physicists made crystal lattice from polaritons
20.03.2018 | ITMO University

nachricht Mars' oceans formed early, possibly aided by massive volcanic eruptions
20.03.2018 | University of California - Berkeley

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: Mars' oceans formed early, possibly aided by massive volcanic eruptions

Oceans formed before Tharsis and evolved together, shaping climate history of Mars

A new scenario seeking to explain how Mars' putative oceans came and went over the last 4 billion years implies that the oceans formed several hundred million...

Im Focus: Tiny implants for cells are functional in vivo

For the first time, an interdisciplinary team from the University of Basel has succeeded in integrating artificial organelles into the cells of live zebrafish embryos. This innovative approach using artificial organelles as cellular implants offers new potential in treating a range of diseases, as the authors report in an article published in Nature Communications.

In the cells of higher organisms, organelles such as the nucleus or mitochondria perform a range of complex functions necessary for life. In the networks of...

Im Focus: Locomotion control with photopigments

Researchers from Göttingen University discover additional function of opsins

Animal photoreceptors capture light with photopigments. Researchers from the University of Göttingen have now discovered that these photopigments fulfill an...

Im Focus: Surveying the Arctic: Tracking down carbon particles

Researchers embark on aerial campaign over Northeast Greenland

On 15 March, the AWI research aeroplane Polar 5 will depart for Greenland. Concentrating on the furthest northeast region of the island, an international team...

Im Focus: Unique Insights into the Antarctic Ice Shelf System

Data collected on ocean-ice interactions in the little-researched regions of the far south

The world’s second-largest ice shelf was the destination for a Polarstern expedition that ended in Punta Arenas, Chile on 14th March 2018. Oceanographers from...

All Focus news of the innovation-report >>>



Industry & Economy
Event News

Virtual reality conference comes to Reutlingen

19.03.2018 | Event News

Ultrafast Wireless and Chip Design at the DATE Conference in Dresden

16.03.2018 | Event News

International Tinnitus Conference of the Tinnitus Research Initiative in Regensburg

13.03.2018 | Event News

Latest News

Physicists made crystal lattice from polaritons

20.03.2018 | Physics and Astronomy

Mars' oceans formed early, possibly aided by massive volcanic eruptions

20.03.2018 | Physics and Astronomy

Thawing permafrost produces more methane than expected

20.03.2018 | Earth Sciences

Science & Research
Overview of more VideoLinks >>>