Research Stories

by Joe Kullman

The world can get fantastically bizarre when you wander mentally out to the edge of the theoretical dimensions of physics. In fact, thinking about the nanoscale universe is mind bending.

Imagine you place a bowling ball next to a concrete wall. You leave it there and return later. No one else has been there, but the bowling ball is now on the other side of the wall. It moved itself there atom by atom, electron by electron, through the wall.

Of course, such movement is highly, highly, highly improbable. It would take a period of time close to the lifetime of the universe to happen—if it ever did. However, Nathan Newman says that such an event is not altogether impossible, theoretically. Newman is professor in ASU’s School of Materials and the departments of electrical engineering and physics. He also is director of the LeRoy Eyring Center for Solid State Science.

Infinitesimal matter behaves differently, Newman explains. Quantum mechanics kicks in with matter at its smallest dimensions. “The idea of the atoms and electrons of objects moving through barriers like concrete walls actually becomes more conceivable,” he says.

Wrap your mind around that concept. Got it? Only then can you begin to understand some aspects of the research done by Newman’s group. His team includes electrical engineers, physicists, materials scientists, and chemists. Their job is to manipulate atoms and electrons and explore the behavior of matter at the nanoscale.

“We are trying to understand the most basic physical properties of materials and the matter that makes them up at the nanoscale level,” Newman explains. “This is about going into the unknown, where the thrill and reward can be in discovering things you don’t expect.”

Explorations by ASU researchers can and do circle back to the practical realm. This is where the nanotechnological possibilities promise significant advances.

Nanotechnology is at the core of the center’s research efforts. These ASU scientists study mechanisms that will expand the powers of electronics. They work to improve the capabilities of computers, cell phones, and other devices that currently use semiconductors.

“You can use nanotechnology to make electronic components smaller,” Newman says. “When critical dimensions are kept to the thickness of just a few atomic layers, new possibilities open up. We can make devices that operate a thousand times faster and use less power."

ASU researchers are studying “tunneling” at the nanoscale level. Tunneling may provide a way to enhance the speed of digital computer logic and improve the density of magnetic memory storage.

A major hurdle stands in the way. Electrons don’t have the energy to make the jump across the spaces between components in electronic devices. Newman and his colleagues are experimenting with construction of nanodevices to create advanced “tunnel junctions.” Such junctions would harness the pull of magnetism and electrical charge. They actually build a transport path for those electrons to hop among components.

This possibility rests on “the quantum mechanical nature” of electrons. “Quantum mechanics allows electrons to travel across regions where they do not have sufficient energy to go on their own,” Newman says.

With magnetic tunneling, the idea is to, in effect, grab the magnetized electrons out of that suspended state and pull them where you want them to go. The ASU researchers don’t expect to be able transport a bowling ball through a brick wall. But the applications of such techniques could be far-ranging.

By gaining nanoscale control of electron tunneling and other quantum phenomena in magnets, semiconductors and superconductors, scientists will be a step closer to advancing the portability and effectiveness of many forms of critical technology, Newman says. Having that control could enhance the speed of computers and allow computer memory and logic functions to be performed by the same components, instead of by separate arrays.

Other facets of the technology could prove beneficial as well. It could improve the magnetic resonance imaging (MRI) devices so widely used in medical care today. It could also enhance the performance of microwave communications systems and the electron and ion accelerators essential to advanced scientific research.

Such impacts only scratch the surface of where nanoscience and nanoengineering may lead. In his area of expertise, Newman says, “We are digging deeper into the fundamental nature of solid materials. It’s not overstating things to say it might open up a universe of new possibilities.”

Read the first story in this series, "To the edge of infinity...and beyond!"