Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Magnetic flux quanta get a dance lesson

03.03.2008
Alternating electric current can be used to precisely control tiny vortices of magnetism

Swirling cyclones of magnetism at the sub-micron scale that can trouble superconducting devices have been tamed by RIKEN scientists. Their technique could help to minimize magnetic noise in sensitive superconducting detectors, and could even help to build a new generation of devices for supercomputers.

When cooled below a critical temperature, superconductors carry electricity with no resistance. But magnetic fields can disrupt this behavior by introducing magnetic flux quanta into the material. These quanta, also known as vortices, are the basic units of magnetism, just as the charge of an electron is the fundamental unit of electricity.

Scientists can control how these vortices move by introducing tiny traps, or nano-holes, into the structure of the superconducting material. But since the pattern of these tiny traps is fixed once the device is made, it’s a relatively inflexible approach that restricts the way the vortices can be moved around.

Now, a team including Franco Nori and Sergey Savel’ev of RIKEN’s Frontier Research System in Wako, have shown how to precisely control the movement of magnetic flux quanta with an alternating electric current (AC)1.

The scientists tested the method on a high-temperature superconductor made from bismuth, strontium, calcium and copper (Bi2Sr2CaCu2O8 + ä). When the electrical current oscillates back and forth, the vortices obediently follow their rhythm.

Nori, also based at University of Michigan, US, says that the technique is like leading the magnetic flux quanta through a series of dance steps (Fig. 1). “The applied current acts as the leading dance partner and the vortices follow the steps imposed by the current,” he says.

More complicated rhythms are created by adding more overlapping alternating currents, allowing the scientists to steer their magnetic flux quanta through the material. “The two ‘control knobs’ we use are the ratio of the AC frequencies, and the relative phase difference between them,” explains Nori.

Savel’ev, also at Loughborough University, UK, adds: “By slowly varying either one of these two control knobs, vortices are pushed either in one direction or the opposite.”

Nori says that the technique could also be used to manipulate trapped ions, moving electrons around in certain types of crystal, or even separating different types of very tiny particles.

In the longer term, the scientists hope that the technique could contribute to the burgeoning field of ‘fluxtronics’—moving magnetic quanta around to manipulate computer data. This would potentially be much faster that conventional methods relying on shuttling electrons between transistors.

1. Ooi, S., Savel'ev, S., Gaifullin, M. B., Mochiku, T., Hirata, K. & Nori, F. Nonlinear nanodevices using magnetic flux quanta. Physical Review Letters 99, 207003 (2007).

Saeko Okada | ResearchSEA
Further information:
http://www.rikenresearch.riken.jp/research/391/
http://www.researchsea.com

More articles from Physics and Astronomy:

nachricht A better way to weigh millions of solitary stars
15.12.2017 | Vanderbilt University

nachricht A chip for environmental and health monitoring
15.12.2017 | Friedrich-Alexander-Universität Erlangen-Nürnberg

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: First-of-its-kind chemical oscillator offers new level of molecular control

DNA molecules that follow specific instructions could offer more precise molecular control of synthetic chemical systems, a discovery that opens the door for engineers to create molecular machines with new and complex behaviors.

Researchers have created chemical amplifiers and a chemical oscillator using a systematic method that has the potential to embed sophisticated circuit...

Im Focus: Long-lived storage of a photonic qubit for worldwide teleportation

MPQ scientists achieve long storage times for photonic quantum bits which break the lower bound for direct teleportation in a global quantum network.

Concerning the development of quantum memories for the realization of global quantum networks, scientists of the Quantum Dynamics Division led by Professor...

Im Focus: Electromagnetic water cloak eliminates drag and wake

Detailed calculations show water cloaks are feasible with today's technology

Researchers have developed a water cloaking concept based on electromagnetic forces that could eliminate an object's wake, greatly reducing its drag while...

Im Focus: Scientists channel graphene to understand filtration and ion transport into cells

Tiny pores at a cell's entryway act as miniature bouncers, letting in some electrically charged atoms--ions--but blocking others. Operating as exquisitely sensitive filters, these "ion channels" play a critical role in biological functions such as muscle contraction and the firing of brain cells.

To rapidly transport the right ions through the cell membrane, the tiny channels rely on a complex interplay between the ions and surrounding molecules,...

Im Focus: Towards data storage at the single molecule level

The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.

Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

AKL’18: The opportunities and challenges of digitalization in the laser industry

07.12.2017 | Event News

 
Latest News

Engineers program tiny robots to move, think like insects

15.12.2017 | Power and Electrical Engineering

One in 5 materials chemistry papers may be wrong, study suggests

15.12.2017 | Materials Sciences

New antbird species discovered in Peru by LSU ornithologists

15.12.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>