A team of Ohio State researchers has received a $6.34 million award from the Defense Advanced Research Projects Agency (DARPA) to develop novel magnetic materials by unlocking the power of skyrmions, nanoscale spin textures that offer promise for storage miniaturization.
The Ohio State collaborators are one of a handful of successful teams to win this award in an international competition as part of DARPA’s Topological Excitations in Electronics (TEE) program. TEE endeavors to design materials with new, controllable functionalities in memory, logic, sensors and quantum information processing — all having critical implications for the nation’s economic, energy and defense security.
In magnetic memories, information (for example, a collection of bits) is stored as clusters of spins, which are either an up or a down (or put differently, a one or a zero). These spin clusters, which form the basis of magnetic memories, become less stable when reduced in size.
“As the spin clusters become smaller and smaller, the memory becomes volatile,” says Mohit Randeria, professor of physics and principal investigator on the DARPA grant. “Even minor fluctuations due to thermal disturbances at room temperature could lead to spin directions flipping and information being lost.”
Randeria says that skyrmions, topologically stable spin textures, could be the key for creating smaller magnetic information storage that is still stable and efficient. He says a skyrmion is like a nanoscale “whirlpool” of spins in the magnetization texture. Skyrmions behave like particles that can be created, moved and manipulated, and they are stable at room temperature. As a result, they offer great promise for magnetic information storage in miniaturized applications.
In addition, skyrmion-based memories are likely to be more energy efficient than conventional magnetic memories, meaning that a smaller current is needed to read, write or manipulate the information.
“You want magnetic storage to maintain stability and robustness. You want it to be immune to fluctuation so it’s not volatile,” Randeria says. “You also want to be able to store as many bits as possible in a small area so you can miniaturize, and you want energy-efficient ways to manipulate these bits. Skyrmions seem to satisfy all of these criteria.”