IBM Explores Copper Magnetism for Use in Memory

TORONTO — Every innovation in memory technology begins with basic research, and a team at IBM Research has developed new technique to control the magnetism of a single copper atom. The technology could one day allow individual atomic nuclei to store and process information, but there’s a long path ahead to any form of commercialization.

In a paper recently published in the journal Nature Nanotechnology, IBM Research scientists Dr. Christopher Lutz and Dr. Kai Yang demonstrated how they can control the magnetism of a single atom’s nucleus by performing Nuclear Magnetic Resonance (NMR) one atom at a time. NMR is an essential tool for determining the structures of molecules, but the work by Lutz and Yang is the first time NMR has been achieved using a Scanning Tunneling Microscope (STM), the Nobel Prize-winning IBM invention that allows atoms to be viewed and moved individually.

“We're doing basic research in nanotechnology taken to the ultimate limit of the scale of the individual atoms,” explained Lutz in a telephone interview with EE Times. “This is the first time this has been achieved in an environment where we can see the atom and reposition it because we're using a Scanning Tunneling Microscope.”

The STM lets researchers build structures from atoms to test them out so they can understand what they want to build in the future by using a technique called spin resonance.

The STM can image and position each atom to study how the NMR changes and responds to the local environment. By scanning the ultra-sharp tip of the STM's metal needle across the surface, the STM can sense the shape of single atoms and can pull or carry atoms into desired arrangements.

“We are exploring what happens when we probe atoms one at a time and look at their magnetic properties,” said Lutz. “We’ve learned first to sense the magnetic state of a nucleus and then to control it.”

It’s a two-step process. “First we need to align it, so it's not just pointed in random directions,” he said. From there, the researchers manipulated the magnetism of the nucleus by applying radio waves emanating from the tip of a sharp metal needle. The radio waves are tuned precisely to the natural frequency of the nucleus. “Here we're getting access to the nucleus with electric current from the tip,” Lutz said.