Miniature magnets can improve data processing speeds

Materials World magazine
1 Apr 2020

Data processing may be sped up with a new miniature magnet. Idha Valeur finds out more.

Miniature laser-activated magnets could make processing data in cloud computing systems up to 100 times faster, researchers claim. 

The new single-molecule magnetic material was created in a lab environment at the University of Edinburgh, UK. Lecturer in Chemical Physics at the University, Dr Olof Johansson, told Materials World that the main magnetic component is manganese.  

By pulsing a laser on the chemical bond that makes the material magnetic, large files could be loaded, data stored and accessed at much higher speeds if hard drives use these magnets, he explained.   

Overwriting information  

Overwriting information on a hard drive, such as saving a new file, would most likely require a reversal of the north pole to the south pole inside the magnet. Johansson said this is currently achieved using an electromagnet that generates a field strong enough to reverse the magnetisation pole.

‘However, this is a slow and energy-consuming process. Recent work has shown that lasers can do this much faster and, since no currents are involved in energising the electromagnet, it can be more energy efficient as well. We showed that the same mechanism might be possible to achieve in a magnet made from a single molecule,’ he said.  

‘A chemical bond is made from electrons that hold together bonds in a molecule. In this particular molecule, one bond is much weaker than all the others. This makes the molecule magnetic because its north/south pole wants to align along this weaker bond – we call this a  Jahn-Teller axis.   

‘We showed that when we shine light on these molecules, the electrons move around which results in a strengthening of the weak bond at the expense of another, which now becomes weak, and lies along a different axis in the molecule.’ Johansson explained that overwriting should work almost immediately and without much heat loss as the change in electron density along the bonds follows the laser pulse.   

In testing, the team shone short laser pulses at the material and used a second laser pulse to assess the molecule’s response. ‘It showed that the bond’s strength is modulated on very fast timescales,’ Johansson said.  

Less heat  

Current hard drives in cloud-based storage servers require an enormous amount of energy to function and stay cool.  Using the laser-activated magnets in these types of data systems could not only increase the system’s efficiency, processing speeds and capacity, but it could also improve its energy efficiency and reduce carbon emissions as the lasers do not produce any heat. Therefore, Johansson believes that the team’s findings could aid the development of next-generation devices for data storage.   

Johansson noted there is still integral research left to be done and that they are currently exploring how the magnetisation is affected by the change in bond strength. ‘We are also trying to make new molecules to increase the change in the bond after photoexcitation to maximise the change in magnetisation’.