`Honeycombs` of nano sized magnets hold hope for new type of computer processing

Washington - A new material being developed using nano-sized magnets could ultimately lead to new types of electronic devices with greater processing capacity, says a new research.

Tiny magnetic crystals in bacteria are a compass. Many modern data storage devices, like hard disk drives, rely on the ability to manipulate the properties of tiny individual magnetic sections,  but their overall design is limited by the way these magnetic ‘domains’ interact when they are close together.

Now, researchers from Imperial College London have demonstrated that a honeycomb pattern of nano-sized magnets, in a material known as spin ice, introduces competition between  neighbouring magnets, and reduces the problems caused by these interactions by two-thirds. They have shown that large arrays of these nano-magnets can be used to store computable  information. The arrays can then be read by measuring their electrical resistance.

The scientists have so far been able to ‘read’ and ‘write’ patterns in the magnetic fields, and a key challenge now is to develop a way to utilise these patterns to perform calculations, and to  do so at room temperature. At the moment, they are working with the magnets at temperatures below minus 223°C.

Research author Dr Will Branford and his team have been investigating how to manipulate the magnetic state of nano-structured spin ices using a magnetic field and how to read their state  by measuring their electrical resistance.

They found that at low temperatures (below minus 223oC) the magnetic bits act in a collective manner and arrange themselves into patterns. This changes their resistance to an electrical  current so that if one is passed through the material, this produces a characteristic measurement that the scientists can identify.

Current technology uses one magnetic domain to store a single bit of information. The new finding suggests that a cluster of many domains could be used to solve a complex computational  problem in a single calculation.

“Electronics manufacturers are trying all the time to squeeze more data into the same devices, or the same data into a tinier space for handheld devices like smart phones and mobile  computers,” said Dr Branford, an EPSRC Career Acceleration Fellow in the Department of Physics at Imperial College London.

“However, the innate interaction between magnets has so far limited what they can do. In some new types of memory, manufacturers try to avoid the limitations of magnetism by avoiding  using magnets altogether, using things like ferroelectric (flash) memory, memristors or antiferromagnets instead. However, these solutions are slow, expensive or hard to read out.

“Our philosophy is to harness the magnetic interactions, making them work in our favour,” he said.

Although this research represents a key step forward, researchers say that much more needs to be done before a prototype devices based on this technique can be created.

The study was published in the journal Science.