Associate Professor Yang Hyunsoo (left) and Dr. Shawn Pollard (right) are among the members of the research team that invented a novel ultra-thin multilayer film which could harness the properties of skyrmions as information carriers for storing and processing data on magnetic media. Credit: Siew Shawn Yohanes/NUS website
The National University of Singapore has invented an ultra-thin multilayer film that will help in the design of data storage devices that use less power and work faster than existing memory technologies.
This nano-sized film has the ability to tap the properties of tiny magnetic whirls, known as skyrmions, as information carriers for storing and processing data on magnetic media.
Skyrmions are tiny swirling magnetic textures that are only a few nanometres in size. These are being extensively studied as possible information carriers in next-generation data storage and logic devices.
The invention was developed in collaboration with researchers from Brookhaven National Laboratory, Stony Brook University and Louisiana State University.
“It has long been assumed that there is no DMI in a symmetric structure like the one present in our work, hence, there will be no skyrmion,” said Dr Shawn Pollard from the NUS Department of Electrical and Computer Engineering. “It is really unexpected for us to find both large DMI and skyrmions in the multilayer film we engineered. What’s more, these nanoscale skyrmions persisted even after the removal of an external biasing magnetic field, which are the first of their kind.”
Unique information carriers
The unique information carriers, skyrmions, exist in layered systems, with a heavy metal placed beneath a ferromagnetic material.
Due to the interaction between the different materials, an interfacial symmetry breaking interaction, known as the Dzyaloshinskii-Moriya interaction (DMI), is formed.
Although the formation of DMI helps to stabilise a skyrmion, an absence of an out-of-plane magnetic field can compromise the stability of the skyrmion.
Also, due to the tiny size of the skyrmion, it is difficult to image the nano-sized materials.
The researchers have worked towards creating stable magnetic skyrmions at room temperature without the need for a biasing magnetic field.
“The small size of the skyrmions, combined with the incredible stability generated here, could be potentially useful for the design of next-generation spintronic devices that are energy- efficient and can outperform current memory technologies,” said Associate Professor Yang Hyunsoo from the NUS Department of Electrical and Computer Engineering.
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