麻豆淫院

In a new study, researchers at the University of Minnesota Twin Cities discovered surprising magnetic behavior in one of the thinnest metallic oxide materials ever made. This could pave the way for the next generation of faster and smarter spintronic and quantum computing devices.

The research is in the Proceedings of the National Academy of Sciences.

Using an advanced materials growth technique鈥攈ybrid molecular beam epitaxy鈥攖he researchers created ultra-thin layers of RuO₂, a compound typically known for its metallic but nonmagnetic behavior. By applying epitaxial strain to these atomically thin layers鈥攕imilar to stretching or compressing a rubber band鈥攖hey were able to induce magnetic properties in a material that is otherwise nonmagnetic.

"Our work shows that RuO₂ is not just metallic at the atomic scale鈥攊t's the most metallic material we've observed in any oxide, rivaling even elemental metals and 2D materials, second only to graphene," said Bharat Jalan, the senior author of the study and a professor in the University of Minnesota's Department of Chemical Engineering and Materials Science and holds the Shell Chair.

"What's more exciting is that this is one of the first experimental demonstrations of an altermagnetic state in ultra-thin RuO₂鈥攁 new and exciting class of magnetic material."

One of the key magnetic effects observed is called the anomalous Hall effect, where electrical current bends in the presence of a magnetic field鈥攁n important feature for next-generation memory and data storage devices. Typically, this effect is hard to achieve in metallic RuO₂ and requires extreme magnetic fields, but the researchers were able to observe it in ultra-thin RuO₂ and with much weaker magnetic fields.

"It's exciting because this isn't just a laboratory curiosity鈥攚e're looking at a material that can be integrated into real devices," said Seunnggyo Jeong, a postdoctoral researcher in the Department of Chemical Engineering and Materials Science and first author on the paper. "This could have major implications for developing smaller, faster, and more energy-efficient technologies, directly relevant to artificial intelligence."

The researchers saw magnetic effects in films just two-unit cells thick鈥攖hat's less than a billionth of a meter. And despite being so thin, the material remained highly metallic and structurally stable.

"This discovery shows how we can unlock completely new behaviors in materials just by controlling them at the atomic scale," said Tony Low, a professor in the Department of Electrical and Computer Engineering and co-author on the paper. "Our calculations confirmed that strain changes the internal structure of RuO₂ in just the right way to make this altermagnetic behavior possible."

The team plans to continue exploring how combinations of strain and layering can be used to engineer new material properties. Their ultimate goal is to develop platform materials for future applications in quantum computing, spintronics and low-power electronics.

In addition to Jalan, Jeong, and Low, the University of Minnesota team included Zhifei Yang, Sreejith Nair, Rashmi Choudhary and Juhi Parikh from the Department of Chemical Engineering and Materials Science; along with Seungjun Lee from the Department of Electrical and Computer Engineering. This research was conducted in collaboration with Massachusetts Institute of Technology, Gwangju Institute of Science and Technology and Sungkyunkwan University.