Spintronics would create electronic devices with no electrical currents

Christian Binek sat at his desk on Friday, reviewing new data for the presentation he gave at a conference in France over the weekend.

Binek, an associate professor of physics and astronomy at the University of Nebraska-Lincoln, is the coordinator of a Materials Research Science and Engineering Centers (MRSEC) interdisciplinary research group (IRG) dedicated to finding powerful new ways to store and compute information.

Today, electronic devices rely on electrical currents to store and process data. However, electrical currents produce heat and energy losses, a major problem challenging continued innovation.

Heat is physically harming the device, Binek said.

"As our devices become smaller, the insulators become smaller as well," he said. "When the insulators are smaller, leakage currents occur. If we keep doing what we're doing, it'll be over. Growth will level off."

That's where the IRG comes in. The team explores the spin of electrons and the exploitation of their properties to store data. The team coordinated by Binek involves a number of researchers of different disciplines. Binek has worked closely with Peter Dowben, a chemistry, physics and astronomy professor who analyzes interface properties and measures magnetization at the surface, and Kirill Belashchenko, a physics and astronomy professor and an electronic structure theorist who is working on building models that can be verified experimentally.

"Nebraska has one (MRSEC, funded by the National Science Foundation) and should be very proud of it," Binek said.

He noted that the "competitive" environment mixed with interdisciplinary research is key to success.

Researchers at UNL believe that by changing the magnetization of ferromagnets, engineers can begin developing new "spintronic" devices that store and process large amounts of data without the use of electrical currents.

The researchers at UNL believe they have found a way to detour the use of electric currents to switch atomic spin and the resulting magnetization. The team has determined that when a multilayer atomic structure comes in contact with an electrical field, the field directly flips the magnetization of an atomic magnet at the surface of a non-magnetic material and indirectly provides the desired change in magnetization in the top layers of the structure.

Xi He, one of Binek's graduate students, has worked closely with the team and has conducted many experiments, including one resulting in the recent breakthrough with the multilayer structures. Other researchers have found ways to switch magnetization at incredibly low temperatures.

"This is the first time achieved at room temperature, which makes it useful in real life situations," he said.

However, he noted that the system doesn't function at temperatures higher than 34 degrees Celsius (93.2 F), and that although the team has made breakthroughs they are still in the early stages of creating spintronic devices.

Binek hopes for a maintained "explosion-like growth" in the coming years. In theory, new spintronic devices would allow for more data storage by using less energy.

These devices would not experience dissipated losses in energy over time and because of the absence of destructive electric currents. They would function like new, even decades after purchase.

UNL's MRSEC receives less funding than a larger school, like the University of California, Berkley, Binek said. He smiled and said with confidence, "We can do better than them."

jacobfokken@dailynebraskan.com