New research proposes that atomic-scale magnetic patterns, similar to the spikes of a hedgehog, could result in hard disks with extremely larger capacities than present-day devices.
Magnetic patterns that are similar to a hedgehog’s spikes could lead to more efficient — and larger-scale — data storage, a new study has found. Image credit: Getty Images.
The finding could be a breakthrough for data centers struggling to keep up with the exponentially growing demand for video and cloud data storage.
In a recently published study, scientists at The Ohio State University used a magnetic microscope to picture the patterns, made in thin films of a rare magnetic material, manganese germanide. Details can be found in the journal Science.
In contrast to known magnets such as iron, this material’s magnetism follows helices, resembling the structure of DNA. This results in a new zoo of magnetic patterns with names like hedgehogs, anti-hedgehogs, merons and skyrmions that can be a lot smaller than present-day magnetic bits.
These new magnetic patterns could be used for next-generation data storage. The density of storage in hard disks is approaching its limits, related to how small you can make the magnetic bits that allow for that storage. And that’s motivated us to look for new materials, where we might be able to make the magnetic bits much smaller.
Jay Gupta, Senior Study Author and Professor of Physics, The Ohio State University
To picture the magnetic patterns, Gupta and his team used a scanning tunneling microscope in his lab, adjusted with special tips. This microscope delivers images of the magnetic patterns with atomic resolution. Their images exposed that, in specific parts of the sample, the magnetism at the surface was twisted into a pattern similar to the spikes of a hedgehog.
However, here, the “body” of the hedgehog is just 10 nm wide, which is a lot smaller than present-day magnetic bits (around 50 nm), and almost impossible to envisage. A single human hair is around 80,000 nm thick in comparison.
The researchers also discovered that the hedgehog patterns could be moved on the surface with electric currents, or inverted with magnetic fields. This heralds the reading and writing of magnetic data, potentially using a lot less energy than presently possible.
“There is enormous potential for these magnetic patterns to allow data storage to be more energy efficient,” Gupta said, though he stresses that there is more work to be done before the material could be used on any data storage site.
We have a huge amount of fundamental science still to do about understanding these magnetic patterns and improving how we control them. But this is a very exciting step.
Jay Gupta, Senior Study Author and Professor of Physics, The Ohio State University
This research was financially backed by the Defense Advanced Research Projects Agency, a research division of the U.S. Department of Defense. Other Ohio State scientists who co-authored this study include Jacob Repicky, Adam Ahmed, Po-Kuwan Wu, Mohit Randeria Joseph Corbett, Tao Liu, Tiancong Zhu, Shuyu Cheng and Roland Kawakami.
Journal Reference:
Repicky, J., et al. (2021) Atomic-scale visualization of topological spin textures in the chiral magnet MnGe. Science. doi.org/10.1126/science.abd9225.