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 223oC.
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.
The scientists have so far been able to 'read' and 'write' patterns at room temperature. However, at the moment the collective behaviour is only seen at temperatures below minus 223oC. A key challenge now is to develop a way to utilise these patterns to perform calculations, and to do so at room temperature.