Building computers from magnetic tornadoes

Researchers at the University of Sheffield’s Department of Materials Science and Engineering are investigating ways that magnetic devices hundreds of times thinner than a human hair can be used in next-generation computing technologies.

Dr Tom Hayward and his PhD student Khalid Omari propose a new technology that could reduce the power consumption of computers, making their batteries last longer and reducing their impact on the environment.

Magnetic materials form the basis of most hard disk drives and store the vast majority of the incredible 2.7 zettabytes (2.7 followed by 21 zeros) ‘bits’ of data that are currently held worldwide. The usefulness of magnetic materials for data storage stems from a property known as non-volatility, the ability of a material to retain information without consuming energy.

Recently scientists have begun to investigate whether magnetic materials can also be used to perform calculations and so take on the role of a computer’s CPU as well as its long-term memory. A computer built around this technology should be much more power efficient than existing technologies.

In a recent publication in Physical Review Applied, Dr Hayward and his research group have taken steps towards this goal by presenting simulations demonstrating magnetic ‘logic gates’, the fundamental building blocks of a CPU.

In wires of magnetic material, two hundred times thinner than a human hair, magnetism can form into swirling ‘tornadoes’ of magnetisation known as magnetic vortex domain walls. In their simulations, researchers use vortices where the magnetism turns clockwise to represent ‘0’ and vortices where it turns anticlockwise to represent ‘1’, allowing them to encode binary data. The vortices are then flowed through the wires using and interacted with carefully defined features in the wires that recreate the function of logic gates.

“I’m delighted with the results of our research. While this technology is at a very early stage, and a huge amount of work is still to be done, we have demonstrated an entirely new way of both storing and processing information. We’re now looking forward to moving towards experimental prototypes and exploring whether we can make real devices that are much more power efficient than those in current computers,” said Dr Hayward.

The group now plan to build experimental prototypes of the logic gates and to investigate whether they can be made smaller and operate faster. All of these will be critical steps in realising their concept as a real technology.