Nanotechnology Now

Our NanoNews Digest Sponsors





Heifer International

Wikipedia Affiliate Button


DHgate

Home > Press > Whirlpools on the Nanoscale Could Multiply Magnetic Memory: At the Advanced Light Source, Berkeley Lab scientists join an international team to control spin orientation in magnetic nanodisks

The electron spins in a magnetic vortex all point in parallel, either clockwise or counterclockwise. Spins in the crowded core of the vortex must point out of the plane, either up or down. The four orientations of circularity and polarity could form the cells of multibit magnetic storage and processing systems.
The electron spins in a magnetic vortex all point in parallel, either clockwise or counterclockwise. Spins in the crowded core of the vortex must point out of the plane, either up or down. The four orientations of circularity and polarity could form the cells of multibit magnetic storage and processing systems.

Abstract:
"We spent 15 percent of home energy on gadgets in 2009, and we're buying more gadgets all the time," says Peter Fischer of the U.S. Department of Energy's Lawrence Berkeley National Laboratory (Berkeley Lab). Fischer lets you know right away that while it's scientific curiosity that inspires his research at the Lab's Advanced Light Source (ALS), he intends it to help solve pressing problems.

Whirlpools on the Nanoscale Could Multiply Magnetic Memory: At the Advanced Light Source, Berkeley Lab scientists join an international team to control spin orientation in magnetic nanodisks

Berkeley, CA | Posted on May 22nd, 2013

"What we're working on now could make these gadgets perform hundreds of times better and also be a hundred times more energy efficient," says Fischer, a staff scientist in the Materials Sciences Division. As a principal investigator at the Center for X-Ray Optics, he leads ALS beamline 6.1.2, where he specializes in studies of magnetism.

Fischer recently provided critical support to a team led by Vojtĕch Uhlíř of the Brno University of Technology in the Czech Republic and the Center for Magnetic Recording Research at the University of California, San Diego. Researchers from both institutions and from Berkeley Lab used the unique capabilities of beamline 6.1.2 to advance a new concept in magnetic memory.

"Magnetic memory is at the heart of most electronic devices," says Fischer, "and from the scientist's point of view, magnetism is about controlling electron spin."

Magnetic memories store bits of information in discrete units whose electron spins all line up in parallel, pointing one way or the opposite to signify a one or a zero. What Fischer and his colleagues propose is multibit storage in which each unit has four states instead of two and can store twice the information.

The key is magnetic vortices - whirlpools of magnetic field - confined to tiny metal disks a few billionths of a meter (nanometers) in diameter. The electron spins are seeking the lowest possible energy; spins that point in opposing directions, antiparallel, cost energy. Thus the electrons line up with all their spins pointing in a circle, either clockwise or counterclockwise around the disk.

In the core of the vortex, however, where the circles get smaller and smaller and neighboring spins would inevitably align antiparallel, they tend to tilt out of the plane, pointing either up or down.

"So each disk has four bits instead of two - left or right circularity and up or down polarity of the core - but you must be able to control the orientation of each independently," says Fischer.

Up, down, and around - taking control

Applying a strong, steady external magnetic field can reverse core polarity, but practical devices can't tolerate strong fields, and they need faster switches. Previous researchers at the ALS had found that with weak oscillating magnetic fields in the plane of the nanodisk they could quickly nudge the core out of its central position and get the same result.

"Instead of a static field, you wiggle it," Fischer explains. As the core is pushed away from the center of the disk, successive magnetic waves - changes in spin orientation - move the core faster and faster until its polarity flips to the opposite orientation.

The team used ALS beamline 6.1.2 to demonstrate, for the first time, that similar methods can control the circularity of the magnetic vortices.

In this case, the "wiggle" drives the core right off the edge of the disk. Once it's expelled, the vortex collapses and reforms, with spins pointing in the opposite direction: clockwise instead of counterclockwise, or vice versa.

Beamline 6.1.2 specializes in soft x-ray transmission microscopy of magnetic states, which allowed the researchers to make direct images of how the strength and duration of the trains of electric and magnetic pulses affected the circularity of the vortex. They found that control depends on the disk's geometry.

The disks were all tapered, with diagonal slices off their top surfaces that served to accelerate the core, once it started moving. But thickness and diameter were the important factors: the smaller the disk, the better.

"Thick" disks (30 nanometers) over a thousand nanometers in diameter were sluggards, taking more than three nanoseconds to switch circularity. But disks only 20 nanometers thick and 100 nanometers across could switch orientation in less than half a nanosecond.

Much remains to be done before the four-value multibit becomes practical, Polarity can be controlled, and circularity can be controlled, but so far they can't be controlled at the same time. Plans for doing this are in the works.

"This is the scientific basis for possible applications to come," says Fischer. "We are already looking at ways to control spin with temperature and voltage, at how to completely decouple spin from charge currents, and even at ways to couple chains of nanodisks together to build logic devices - not just for memory, but for computation."

In Fischer's opinion, the ALS's soft x-ray microscopes tools are in the pole position for the race in magnetism research. "No method besides x-ray microscopy can provide similarly comprehensive information, both to identify the magnetic materials and to image the fastest dynamics of magnetic states on the nanoscale. The instruments we have are unique and serve the whole vortex community, world-wide."

DOE's Office of Science supports the ALS and, with the European Regional Development Fund and the Grant Agency of the Czech Republic, supported this research.

####

About DOE/Lawrence Berkeley National Laboratory
Lawrence Berkeley National Laboratory addresses the world’s most urgent scientific challenges by advancing sustainable energy, protecting human health, creating new materials, and revealing the origin and fate of the universe. Founded in 1931, Berkeley Lab’s scientific expertise has been recognized with 13 Nobel prizes. The University of California manages Berkeley Lab for the U.S. Department of Energy’s Office of Science. For more, visit www.lbl.gov.

The Advanced Light Source is a third-generation synchrotron light source producing light in the x-ray region of the spectrum that is a billion times brighter than the sun. A DOE national user facility, the ALS attracts scientists from around the world and supports its users in doing outstanding science in a safe environment. For more information visit www-als.lbl.gov/.

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 the Office of Science website at science.energy.gov.

For more information, please click here

Contacts:
Paul Preuss

510-486-6249

Copyright © DOE/Lawrence Berkeley National Laboratory

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related Links

“Dynamic switching of the spin circulation in tapered magnetic nanodisks,” by Vojtĕch Uhlíř, Michal Urbánek, Lukáš Hladík, Jiří Spousta, Mi-Young Im, Peter Fischer, Nasim Eibagi, Jimmy Kan, Eric E. Fullerton, and Tomáš Šikola, appears in advance online publication of Nature Nanotechnology at:

For more about Fischer’s research on magnetic vortices, visit:

Visit for more about the Center for X-Ray Optics:

Related News Press

News and information

Seeing quantum motion August 30th, 2015

Artificial leaf harnesses sunlight for efficient fuel production August 30th, 2015

Researchers use DNA 'clews' to shuttle CRISPR-Cas9 gene-editing tool into cells August 30th, 2015

Draw out of the predicted interatomic force August 30th, 2015

Imaging

Nanolab Technologies LEAPS Forward with High-Performance Analysis Services to the World: Nanolab Orders Advanced Local Electrode Atom Probe (LEAP®) Microscope from CAMECA Unit of AMETEK Materials Analysis Division August 27th, 2015

50 Years of Scanning Electron Microscopy from ZEISS: ZEISS celebrates the birth of the first commercial scanning electron microscope in 1965 August 26th, 2015

Announcing Oxford Instruments and School of Physics signing a Memorandum of Understanding August 26th, 2015

Kwansei Gakuin University in Hyogo, Japan, uses Raman microscopy to study crystallographic defects in silicon carbide wafers August 25th, 2015

Laboratories

Major innovation in molecular imaging delivers spatial and spectral info simultaneously: Berkeley Lab scientist invents technique to combine spectroscopy with super-resolution microscopy, enabling new ways to examine cell structures and study diseases August 17th, 2015

Drexel engineers 'sandwich' atomic layers to make new materials for energy storage August 15th, 2015

Surprising discoveries about 2-D molybdenum disulfide: Berkeley Lab researchers use award-winning campanile probe on promising semiconductor August 15th, 2015

New ORNL hybrid microscope offers unparalleled capabilities August 10th, 2015

Govt.-Legislation/Regulation/Funding/Policy

Seeing quantum motion August 30th, 2015

Artificial leaf harnesses sunlight for efficient fuel production August 30th, 2015

Researchers use DNA 'clews' to shuttle CRISPR-Cas9 gene-editing tool into cells August 30th, 2015

Draw out of the predicted interatomic force August 30th, 2015

Spintronics

Spintronics: Molecules stabilizing magnetism: Organic molecules fixing the magnetic orientation of a cobalt surface/ building block for a compact and low-cost storage technology/ publication in Nature Materials July 25th, 2015

Penn researchers discover new chiral property of silicon, with photonic applications July 25th, 2015

Spintronics just got faster July 20th, 2015

Fundamental observation of spin-controlled electrical conduction in metals: Ultrafast terahertz spectroscopy yields direct insight into the building block of modern magnetic memories July 6th, 2015

Chip Technology

Nanometrics to Participate in the Citi 2015 Global Technology Conference August 26th, 2015

Kwansei Gakuin University in Hyogo, Japan, uses Raman microscopy to study crystallographic defects in silicon carbide wafers August 25th, 2015

A little light interaction leaves quantum physicists beaming August 25th, 2015

'Magic' sphere for information transfer: Professor at the Lomonosov Moscow State University made the «magic» sphere for information transfer August 24th, 2015

Memory Technology

'Magic' sphere for information transfer: Professor at the Lomonosov Moscow State University made the «magic» sphere for information transfer August 24th, 2015

Superlattice design realizes elusive multiferroic properties: New design sandwiches a polar metallic oxide between an insulating material August 23rd, 2015

High-precision control of nanoparticles for digital applications August 19th, 2015

Scientists achieve major breakthrough in thin-film magnetism August 17th, 2015

Discoveries

Seeing quantum motion August 30th, 2015

Artificial leaf harnesses sunlight for efficient fuel production August 30th, 2015

Researchers use DNA 'clews' to shuttle CRISPR-Cas9 gene-editing tool into cells August 30th, 2015

Draw out of the predicted interatomic force August 30th, 2015

Announcements

Seeing quantum motion August 30th, 2015

Artificial leaf harnesses sunlight for efficient fuel production August 30th, 2015

Researchers use DNA 'clews' to shuttle CRISPR-Cas9 gene-editing tool into cells August 30th, 2015

Draw out of the predicted interatomic force August 30th, 2015

Interviews/Book Reviews/Essays/Reports/Podcasts/Journals/White papers

Seeing quantum motion August 30th, 2015

Researchers use DNA 'clews' to shuttle CRISPR-Cas9 gene-editing tool into cells August 30th, 2015

Draw out of the predicted interatomic force August 30th, 2015

Iranian Scientists Use Artemisia Annua Plant to Produce Breast Cancer Drugs August 29th, 2015

Tools

Nanolab Technologies LEAPS Forward with High-Performance Analysis Services to the World: Nanolab Orders Advanced Local Electrode Atom Probe (LEAP®) Microscope from CAMECA Unit of AMETEK Materials Analysis Division August 27th, 2015

Nanometrics to Participate in the Citi 2015 Global Technology Conference August 26th, 2015

50 Years of Scanning Electron Microscopy from ZEISS: ZEISS celebrates the birth of the first commercial scanning electron microscope in 1965 August 26th, 2015

Announcing Oxford Instruments and School of Physics signing a Memorandum of Understanding August 26th, 2015

Research partnerships

Nanocatalysts improve processes for the petrochemical industry August 28th, 2015

Announcing Oxford Instruments and School of Physics signing a Memorandum of Understanding August 26th, 2015

Researchers combine disciplines, computational programs to determine atomic structure August 26th, 2015

Developing Component Scale Composites Using Nanocarbons August 26th, 2015

NanoNews-Digest
The latest news from around the world, FREE



  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project







Car Brands
Buy website traffic