Processing and Storage With Nanomagnets
Just as so many people are looking at solid state drives as the preferred storage method of the future, researchers at the Imperial College London have to find something to make magnetic hard drives interesting again. The classic hard drive stores data in magnetic domains along platters. The direction of the magnetic field from the domain is what determines if a bit is zero or one. The researchers found a new pattern for the domains which may allow the domains to shrink, and enable data processing on the drive itself.
Cobalt bar magnets just one micon long (millionth of a meter) and 100 nanometers wide were arranged in a honeycomb pattern. A unit in this array is where three of these magnets meet, and because the end of a magnet is only positive or negative, at least one magnet is repelled by another in the unit. This arrangement is called a frustrated magnetic system, and there are six configurations a unit can have with the same amount of frustration. With more units the complexity of the system increases exponentially.
Previous research has shown it is possible to flip a single bar in a unit with an external magnetic field. What the researchers at ICL found is that a current passing through the pattern is affected by it. If you change the configuration of one unit to another, the resistance to the current also changes. This allowed the researchers to not only write data to the magnetic network, but to process a signal with it.
The catch is this was only accomplished at 50 K or -223 ºC. Data can still be written to and read from the network at room temperature, but the signal processing might not work. However, the researchers are confident we will see this technology in 10-15 years.