Discovery could expand number of materials used in next-gen computing

Using a nitrogen-vacancy (NV) scanning probe at the University of Nebraska-Lincoln College of Engineering, an international team made a breakthrough discovery in single-layer metal films that could expand the number of magnetic materials that can be used as memory and logic elements for next-generation energy-efficient memory and logic devices. The goal is to develop more energy efficient devices.

In the laboratory of Abdelghani Laraoui, assistant professor of mechanical and materials engineering, researchers achieved the first demonstration of imaging magnetic skyrmions - tiny, swirling vortex-like quasiparticles - at room temperature in ferromagnetic magnetic materials that contain a gradient composition.

"In the past, scientists needed low temperatures to observe such spin textures and there is a limited family of materials that we can use at room temperature," Laraoui said.

Traditional hard disk drives (HDD) use the direction of the magnetization of magnetic materials as binary data bits, analogous to the binary resistive state of transistors. The magnetization can be controlled with magnetic field or current, enabling high density data storage. However, when the magnetic bits get smaller, they are more susceptible to thermal noise and defects present in the material that can disrupt or destroy the stored information stored.

UNL team members include Jeffrey Shield, department chair and professor of mechanical and materials engineering; materials engineering graduate students Adam Erickson and Suchit Sarin; and physics researchers Hamed Vakili, Suvechhya Lamichhane, Edward Schwartz, Sy-Hwang Liou and Alexey Kovalev. The team also includes researchers from National University of Singapore, Lanzhou University in China and the University of Latvia.

Manipulating this interaction with various currents can create spins that make next-generation computing and memory devices work more efficiently. Demonstrating this at room temperature and with less-expensive materials will change the future for next-generation computing, memory and logic devices, Laraoui said.

"This experience has been so exciting because of its potential, and because we achieved it here, in Nebraska," Laraoui said. "Only a few places have this equipment available."

The research is summarized in the Oct. 28 edition of the journal, ACS Nano.