Researchers improve ability to write and store information on electronic devices

Sep 13, 2007
Researchers improve ability to write and store information on electronic devices
Matthias Bode, Center for Nanoscale Materials, is shown with his enhanced spin polarized scanning tunneling microscope (SP-STM). His enhanced technique allows scientists to observe the magnetism of single atoms. Use of this method could lead to better magnetic storage devices for computers and other electronics. Credit: DOE/Argonne National Laboratory

New research led by the U.S. Department of Energy's Argonne National Laboratory physicist Matthias Bode provides a more thorough understanding of new mechanisms, which makes it possible to switch a magnetic nanoparticle without any magnetic field and may enable computers to more accurately write and store information.

Bode and four colleagues at the University of Hamburg used a special scanning tunneling microscope equipped with a magnetic probe tip to force a spin current through a small magnetic structure. The researchers were able to show that the structure's magnetization direction is not affected by a small current, but can be influenced if the spin current is sufficiently high.

Most computers today use dynamic random access memory, or DRAM, in which each piece of binary digital information, or bit, is stored in an individual capacitor in an integrated circuit. Bode's experiment focused on magneto-resistive random access memory, or MRAM, which stores data in magnetic storage elements consisting of two ferromagnetic layers separated by a thin non-magnetic spacer. While one of the two layers remains polarized in a constant direction, the other layer becomes polarized through the application of an external magnetic field either in the same direction as the top layer (for a "0") or in the opposite direction (for a "1").

Traditionally, MRAM are switched by magnetic fields. As the bit size has shrunk in each successive generation of computers in order to accommodate more memory in the same physical area, however, they have become more and more susceptible to "false writes" or "far-field" effects, Bode said. In this situation, the magnetic field may switch the magnetization not only of the target bit but of its neighbors as well. By using the tip of the Scanning Tunneling Microscope (STM), which has the potential to resolve structures down to a single atom, the scientists were able to eliminate that effect.

Bode and his colleagues were the first ones who did such work with an STM that generates high spatial-resolution data. "If you now push just a current through this bit, there's no current through the next structure over," Bode said. "This is a really local way of writing information."

The high resolution of the STM tip might enable scientists to look for small impurities in the magnetic storage structures and to investigate how they affect the magnet's polarization. This technique could lead to the discovery of a material or a method to make bit switching more efficient. "If you find that one impurity helps to switch the structure, you might be able to intentionally dope the magnet such that it switches at lower currents," Bode said.

Results of this research were published in the September 14 issue of Science and related research was published earlier this year in Nature.

Source: Argonne National Laboratory

Explore further: Caging of molecules allows investigation of equilibrium thermodynamics

add to favorites email to friend print save as pdf

Related Stories

Why can't we design the perfect spacesuit?

Feb 19, 2015

So far, every spacesuit humans have utilized has been designed with a specific mission and purpose in mind. As of yet, there's been no universal or "perfect" spacesuit that would fit every need. For example, ...

Electronics you can wrap around your finger

Feb 10, 2015

Electronic devices have shrunk rapidly in the past decades, but most remain as stiff as the same sort of devices were in the 1950s—a drawback if you want to wrap your phone around your wrist when you go ...

Building the next generation of efficient computers

Jan 29, 2015

UConn researcher Bryan Huey has uncovered new information about the kinetic properties of multiferroic materials that could be a key breakthrough for scientists looking to create a new generation of low-energy, ...

Recommended for you

Flexible nanosensors for wearable devices

Feb 25, 2015

A new method developed at the Institute of Optoelectronics Systems and Microtechnology (ISOM) from the Universidad Politécnica de Madrid (UPM) will enable the fabrication of optical nanosensors capable of sticking on uneven ...

New nanowire structure absorbs light efficiently

Feb 25, 2015

Researchers at Aalto University have developed a new method to implement different types of nanowires side-by-side into a single array on a single substrate. The new technique makes it possible to use different ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.