Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Harnessing Magnetic Vortices for Making Nanoscale Antennas


Scientists explore ways to synchronize spins for more powerful nanoscale electronic devices

Scientists at the U.S. Department of Energy's Brookhaven National Laboratory are seeking ways to synchronize the magnetic spins in nanoscale devices to build tiny yet more powerful signal-generating or receiving antennas and other electronics. Their latest work, published in Nature Communications, shows that stacked nanoscale magnetic vortices separated by an extremely thin layer of copper can be driven to operate in unison, potentially producing a powerful signal that could be put to work in a new generation of cell phones, computers, and other applications.

Brookhaven National Laboratory

Stacked nanoscale magnetic vortices (blue and green discs) separated by an extremely thin layer of copper can be driven to oscillate in unison, potentially producing a powerful signal that could be put to work in a new generation of cell phones, computers, and other applications. This illustration shows an array of such stacked vortices, each measuring a few hundred nanometers in diameter.

The aim of this "spintronic" technology revolution is to harness the power of an electron's "spin," the property responsible for magnetism, rather than its negative charge.

"Almost all of today's electronic technology, from the light bulb to the smartphone, involves the movement of charge," said Brookhaven physicist Javier Pulecio, lead author on the new study. "But harnessing spin could open the door for much more compact and novel types of antennas that act as spin wave emitters, signal generators—such as the clocks that synchronize everything that goes on inside a computer—as well as memory and logic devices."

The secret to harnessing spin is to control its evolution and spin configuration.

"If you grab a circular refrigerator magnet and place it under a microscope that could image electron spins, you would see the magnet has several regions called domains, where within each domain all the spins point in the same direction," explained group leader Yimei Zhu. "If you were to shrink that magnet down to a size smaller than a red blood cell, the spins inside the magnet will begin to align themselves into unique spin textures."

For example, in a magnetic disc with a radius of just 500 nanometers (billionths of a meter) and a thickness of just 25 nanometers, the disc can no longer support multiple domains and the spins align in a hurricane-like rotational pattern to reduce the overall magnetic energy. The spins parallel to the disc's surface rotate around a core, much like the eye of the hurricane, either clockwise or anticlockwise. And at the core, the magnetic spins point out of the disc's surface, either up or down. So this structure, a magnetic vortex, has four possible states—up or down paired with clockwise or anticlockwise.

What's more, the core of the magnetic vortex can be moved around within a nanodisc by applying either an electric current or an external magnetic field, "so it behaves much like a particle—a quasi-particle," Pulecio said. Applying certain high-frequency electromagnetic excitations can set the vortex core moving in a circular motion about the center of the disc. These circular motions, or oscillations, are what scientists hope to put to use.

"Magnetic vortex-based oscillators can be tuned to operate at different narrowly defined frequencies, making them extremely flexible for telecommunications applications," Pulecio said. "They are also self-contained elements, about 100,000 times smaller than oscillators based on voltage instead of spin, so they could prove to be less expensive, consuming less electricity, and won't take up as much room on the device. That's especially important if you are talking about miniaturization for cell phones, wearable electronics, tablets, and so on."

For now, however, the power output of these spintronic devices is relatively small compared with oscillator technologies currently in use. So scientists are exploring ways to synchronize the oscillations of multiple magnetic vortices.

In the Nature Communications paper, Pulecio, Zhu, and their collaborators at the Swiss Light Source, Brookhaven's National Synchrotron Light Source, and Stony Brook University explored expanding the device in three dimensions by stacking one vortex on top of another, with the individual discs separated by a thin non-magnetic layer. They investigated how changing the thickness of the non-magnetic layer affected the fundamental interactions at the nanoscale, and how those, in turn, affected the coupled dynamics of the vortices. They directly imaged how the vortices responded to high-frequency stimulation using high-resolution Lorentz transmission electron microscopy imaging.

The results: A thicker separating layer resulted in somewhat unordered motion of the coupled vortices in the two discs. The thinner the separating layer, the stronger the vortices were linked, synching up in space into coherent circular motion. This could help to overcome the power limitations of current vortex-based spintronic antennas by creating arrays of synchronized tiny oscillators through coupled 3D stacks.

The scientists are currently working with other more exotic systems to understand the dynamics in both time and space that could make spintronic technologies a reality.

"Magnetic vortices were one of the first observed magnetic quasi-particles and we are currently looking to expand our investigations to observe other newly discovered spin textures and how we might harness those," Pulecio said.

This research was supported by the Core-Research Programs within Basic Energy Science, DOE Office of Science. Fabrication of the devices was supported in part by the Center for Functional Nanomaterials at Brookhaven National Laboratory.

DOE's Office of Science is the single largest supporter of basic research in the physical sciences in the United States, and is working to address some of the most pressing challenges of our time. For more information, please visit

One of ten national laboratories overseen and primarily funded by the Office of Science of the U.S. Department of Energy (DOE), Brookhaven National Laboratory conducts research in the physical, biomedical, and environmental sciences, as well as in energy technologies and national security. Brookhaven Lab also builds and operates major scientific facilities available to university, industry and government researchers. Brookhaven is operated and managed for DOE's Office of Science by Brookhaven Science Associates, a limited-liability company founded by the Research Foundation for the State University of New York on behalf of Stony Brook University, the largest academic user of Laboratory facilities, and Battelle, a nonprofit applied science and technology organization.

Related Links

Scientific paper: "Coherence and modality of driven interlayer coupled magnetic vortices" DOI: 10.1038/ncomms4760

To see this news release and related graphics on the Brookhaven Lab website, go to:

Karen McNulty Walsh | newswise

More articles from Materials Sciences:

nachricht Coming to a monitor near you: A defect-free, molecule-thick film
27.11.2015 | University of California - Berkeley

nachricht Controlling Electromagnetic Radiation by Graphene
27.11.2015 | Universität Augsburg

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Climate study finds evidence of global shift in the 1980s

Planet Earth experienced a global climate shift in the late 1980s on an unprecedented scale, fuelled by anthropogenic warming and a volcanic eruption, according to new research published this week.

Scientists say that a major step change, or ‘regime shift’, in the Earth’s biophysical systems, from the upper atmosphere to the depths of the ocean and from...

Im Focus: Innovative Photovoltaics – from the Lab to the Façade

Fraunhofer ISE Demonstrates New Cell and Module Technologies on its Outer Building Façade

The Fraunhofer Institute for Solar Energy Systems ISE has installed 70 photovoltaic modules on the outer façade of one of its lab buildings. The modules were...

Im Focus: Lactate for Brain Energy

Nerve cells cover their high energy demand with glucose and lactate. Scientists of the University of Zurich now provide new support for this. They show for the first time in the intact mouse brain evidence for an exchange of lactate between different brain cells. With this study they were able to confirm a 20-year old hypothesis.

In comparison to other organs, the human brain has the highest energy requirements. The supply of energy for nerve cells and the particular role of lactic acid...

Im Focus: Laser process simulation available as app for first time

In laser material processing, the simulation of processes has made great strides over the past few years. Today, the software can predict relatively well what will happen on the workpiece. Unfortunately, it is also highly complex and requires a lot of computing time. Thanks to clever simplification, experts from Fraunhofer ILT are now able to offer the first-ever simulation software that calculates processes in real time and also runs on tablet computers and smartphones. The fast software enables users to do without expensive experiments and to find optimum process parameters even more effectively.

Before now, the reliable simulation of laser processes was a job for experts. Armed with sophisticated software packages and after many hours on computer...

Im Focus: Quantum Simulation: A Better Understanding of Magnetism

Heidelberg physicists use ultracold atoms to imitate the behaviour of electrons in a solid

Researchers at Heidelberg University have devised a new way to study the phenomenon of magnetism. Using ultracold atoms at near absolute zero, they prepared a...

All Focus news of the innovation-report >>>



Event News

Fraunhofer’s Urban Futures Conference: 2 days in the city of the future

25.11.2015 | Event News

Gluten oder nicht Gluten? Überempfindlichkeit auf Weizen kann unterschiedliche Ursachen haben

17.11.2015 | Event News

Art Collection Deutsche Börse zeigt Ausstellung „Traces of Disorder“

21.10.2015 | Event News

Latest News

Siemens to supply 126 megawatts to onshore wind power plants in Scotland

27.11.2015 | Press release

Two decades of training students and experts in tracking infectious disease

27.11.2015 | Life Sciences

Coming to a monitor near you: A defect-free, molecule-thick film

27.11.2015 | Materials Sciences

More VideoLinks >>>