New Approach Exceeds Data Storage Density Limit

December 07, 2017 // By Christoph Hammerschmidt
The miniaturization of storage media is reaching fundamental limits. A new approach has been taken by researchers to use spin crossover molecules as the smallest storage unit. They can store information about their magnetic state. The researchers at the University of Kiel (Germany) have now succeeded in successfully placing such molecules on a surface and thus improving their storage capacity. This would theoretically increase the storage density of conventional hard disks by more than a hundred times.

The use of spin crossover molecules as the smallest storage unit would make it possible to further increase the storage density of data carriers. The challenge is to attach these molecules to surfaces without destroying their storage capacity. A research team from the Christian-Albrechts-University of Kiel (CAU) has now succeeded in doing so. Not only did it successfully launch a new class of spin crossover molecules on a single surface, but it has also been able to exploit interactions that were previously considered obstructive to increase their storage capacity. In theory, this would increase the storage density of conventional hard disks by more than a hundred times and significantly reduce the size of data carriers.

Today, a bit on the hard disk only takes up an area of about 10 x 10 nanometers. However, this is still too large to keep pace with the increasing miniaturization of electronic components. The technology currently used in hard disks for data storage meets a quantum mechanical fundamental limit in the size of a bit. From today's perspective, it cannot achieve further miniaturization, "says Torben Jasper-Tönnies, PhD student in the research group of Professor Richard Berndt at the Institute for Experimental and Applied Physics at CAU. The solution: he and his colleagues are using a single molecule as an example to demonstrate a principle that could enable even smaller hard disks with larger storage capacity in the future. The molecule is only one square nanometer in size. You could already use a 100 times smaller area to store a bit. From the perspective of the Kiel researchers, this would be a step towards shifting the quantum physical limits in storage technology. 

The interdisciplinary research team uses a molecule that can not only be switched between a high and a low magnetic state. Attached to a special surface, it can also be rotated by 45 degrees. Transferred to storage technology, this would allow us to map information to three states, i. e. 0,1 and 2,"explains Jasper-Tönnies. As a storage unit, we would not have a bit but a' trit', so the binary would become a' trinary code'.