06-Feb-2017 - Helmholtz-Zentrum Dresden-Rossendorf (HZDR) e.V.

Three magnetic states for each hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured.

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and the University of Western Australia, designed a special grid structure in a thin layer of cobalt in order to program its magnetic properties. His colleagues from the National University in Singapore produced the grid using a photolithographic process similar to that currently used in chip manufacture. Approximately 250 nanometers sized holes, so-called antidots, were created at regular intervals – with interspaces of only 150 nanometers – in the cobalt layer. In order to be able to stably program it, the Singapore experts followed the Dresden design, which specified a metal layer thickness of approximately 50 nanometers.

At these dimensions the cobalt antidot grid displayed interesting properties: Dr. Bali’s team discovered that with the aid of an externally applied magnetic field three distinct magnetic states around each hole could be configured. The scientists called these states "G", "C" and "Q". Dr. Bali: "Antidots are now in the international research spotlight. By optimizing the antidot geometry we were able to show that the spins, or the magnetic moments of the electrons, could be reliably programmed around the holes."

Building blocks for future logic

Since the individually programmable holes are situated in a magnetic metal layer, the grid geometry has potential use in computers that would work with spin-waves instead of electric current. "Spin-waves are similar to the so-called Mexican waves you see in a football stadium. The wave propagates through the stadium, but the individual fans, in our case the electrons, stay seated", explains Dr. Bali. Logic chips utilizing such spin-waves would use far less power than today’s processors, because no electrical current is involved.

Many magnetic states can be realized in the perforated grid so that the spin-waves can, for example, be assigned specific directions. This could allow for a higher processing speed in future logic chips. "Our perforated grids could also operate as components for future circuits working with spin-waves“, estimates Dr. Bali. Doctoral candidate, Tobias Schneider, is now investigating the dynamics developed by the spin-waves in such perforated grids. Among other aspects he is participating in the development of special computer programs making possible the complex calculation of the magnetic states in perforated grids.

Facts, background information, dossiers
More about Helmholtz-Zentrum Dresden-Rossendorf
  • News

    A new spin in nano-electronics

    In recent years, electronic data processing has been evolving in one direction only: The industry has downsized its components to the nanometer range. But this process is now reaching its physical limits. Researchers at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) are therefore exploring ... more

    Random Access Memory on a Low Energy Diet

    Memory chips are among the most basic components in computers. The random access memory is where processors temporarily store their data, which is a crucial function. Researchers from Dresden and Basel have now managed to lay the foundation for a new memory chip concept. It has the potentia ... more

    A highway for spin waves

    The success story of information processing by way of moving electrons is slowly coming to an end. The trend towards more and more compact chips constitutes a major challenge for manufacturers, since the increasing miniaturization creates partly unsolvable physical problems. This is why mag ... more