Spintronics. If you’ve never heard the word before, it might evoke images of some sort of whirling, whirring, robotized top. Maybe an electro-mechanical gladiator built to compete on Comedy Central’s hit television show “BattleBots.” Or perhaps the kind of glitzy high-tech toy that becomes all the rage each year, heading up many a child’s holiday wish list.
For Jian Wang, a Binghamton University condensed matter physicist, the word “spintronics” did recently mean a high-tech gift, albeit of a different kind. Wang took possession last month of a $1.4 million ion beam deposition system, a room-sized piece of equipment he will use to further his research in the area of spintronics–short for spin-based electronics. The machine was accompanied by an additional $200,000 in related research materials, all donated to the University by the world’s premier manufacturer of computer hard drives, Seagate.
Spintronics is a young research field at the crossroads of physics and electronics. Only about a decade old, it has already begun to fuel quantum leaps in computer technology by harnessing the “spin” of electrons and using that spin to control current and to store information. Within the next five years, spintronics will likely be changing the face of the computer industry, which is why Seagate wants to help Wang along in his research.
“The research Professor Wang is doing in advanced spintronics devices and concepts is very important to Seagate,” said Pat Ryan, executive engineering director, Seagate Head Development. “This research could give Seagate valuable, direct knowledge and data in this emerging field for future product development and could lead to a fundamental change in magnetic devices and storage and computing. The recent ion beam deposition system donation was just Seagate’s way of saying thanks for the work Professor Wang and the University has brought forth.”
Gifts seem to abound when it comes to spintronics and if that isn’t clear by now, just imagine this: within the next five years, the field will be offering up what computer users everywhere might see as the ultimate gift–a rock-solid guarantee against the loss of files, even in the face of a catastrophic loss of power mid-project.
So how does spintronics work? Basically, in addition to mass and charge, electrons have a quantum property called spin. Imagine electrons as perpetually spinning marbles and you’ve got the gist. In ordinary electronic circuits, the orientation of the electrons’ spin, which is labeled either “up” or “down,” is random and has no effect on the flow of current, which is controlled only by the charge. In spintronic devices, however, a defined magnetic field is used to manipulate spin and, in combination with the electron charge, to control the current.
This allows dynamic use of the information that is stored into and carried by electrons as a particular spin orientation. Similar to digital computer’s “0”s and “1”s, spintronic bits are written as “up” or “down” orientations. As a result, spintronics could eventually allow computer manufacturers to replace dynamic random access memory, the Pentium memory chip, and the hard drive in today’s computers with a single chip.
The use of spin itself is not new. The recording industry has for years used magnetic media where information is stored in bits comprising electron spin. But that approach involves very slow access and processing times in information storage, Wang said, and the idea of spintronics is to actively manipulate spin to control the current so that information is controlled and stored as it is processed.
In today’s computers internal memory is used to process information, and external memory is used to store files and data. The two are uncoupled, and shuffling times between them is extremely slow. This also means that if you shut your computer down anything that is being processed and has not yet been shipped to external memory will be lost.
“The idea of spintronics is to eliminate the boundary between external and internal memory,” Wang said. “So in a spintronics device, the information being processed is never lost.”
Wang’s research focuses on developing enabling technologies to use the spin as the controlling mechanism in quantum communication and computing. The purpose of the ion beam deposition system he received from Seagate is to make ultrathin magnetic films in an ultraclean environment. The films control the quality of the interface between the semiconductor and electrode layers in a spintronics device and are critical to the fabrication of electrode structures at the nanometer scale. In order to study the films, Wang’s laboratory needs to be able to produce them, a process that requires vaporization of metal target materials in a complete vacuum so that the vapors settle on a completely smooth surface of a substrate, much like fog on a bathroom mirror.
When Wang talks about ultrathin films, he’s talking on the scale of a nanometer. The width of a human hair is about 10,000 nanometers. Incredibly, vaporizing a single one-pound metal target would probably produce more than enough film of this thickness to cover every single surface of all the buildings on Binghamton’s 870-acre campus. Alternatively, it could cover every single surface of all the rooms of 10 buildings like Science II, Wang said, which is why small quantities of target material are actually vaporized during sample production.
The donated piece of equipment, as well as more than 50 pounds of the “target” materials from which the films are to be vaporized, will make it possible for Wang’s lab to produce in one hour the samples it would have taken him one week to make on his other equipment, he said.
The bottleneck in his research used to be waiting for samples. Thanks to Seagate, he and his research team will now find themselves working to keep up with assessing the qualities and characteristics of the host of samples they can expect to be able to produce.
That’s important, Wang said, because the question of the day is not whether sprintronic devices can be made, but whether they can be made economically. The microelectronics industry has already developed prototypes of nonvolatile random access memory based on spintronics technology, Wang said. His research is likely to help ensure that spintronic devices eventually find their way out of the laboratory and into the marketplace.