By Steve Hamm
A few years ago, when IBM Fellow Stuart Parkin first met Claudia Felser, a formidable scientist who is now his fiance, he risked offending her by dismissing some of her ideas out of hand. “I told her the thing she was working on made no sense at all, but I’ve changed my mind,” he says. “I’m prone to make snap judgments. Sometimes I’m right; sometimes I’m wrong.”
In his own field, solid-state physics, he’s been right more often than not. In fact, he’s being recognized today with the Millennium Technology Prize, one of the world’s most prestigious science honors, by Technology Academy Finland. Previous recipients included Tim Berners-Lee, the inventor of the World Wide Web, and Linus Torvalds, creator of the core elements of Linux, the popular open-source operating system. The Academy cited Stuart’s discoveries in disk drive technology, which have enabled a one-thousand fold increase in the storage capacity of disk drives over the past two decades.
Now Stuart is embarking on a new quest. His goal is to invent electronic devices–which he calls cognitive devices–that will mimic some of the characteristics of the human brain. While Stuart remains an IBM Fellow, he will spend some of his time as a director of the Max Planck Institute of Microstructure Physics in Halle, Germany. Claudia is a director at a different Max Planck institute-her’s in nearby Dresden, Germany. So their relationship not only survived his initial miss-step; it helped redirect the path of Stuart’s career.
In fact, Stuart believes that some of Claudia’s ideas about so-called Heusler materials, which he originally mocked, could have applications in his cognitive-device research. Heusler compounds can, under different conditions, perform as conducting materials or insulating materials, so they have potential for use as components of tiny electronic switches. Stuart is seeking new materials and new device architectures as alternatives to today’s s mainstream silicon semiconductors for computing memory and logic operations.
But we’re getting ahead of ourselves. Let’s backtrack to give you a flavor of where Stuart is coming from, so you can better understand where his intends to go.
Stuart’s doctoral studies and 25 years in IBM Research have been guided by his passion for spintronics, the science of nano-magnetic material properties. Spintronics, the most widely applied flavor of nanotechnology, relies on the spin of electrons rather than their charge to record the zeros and ones that are essential to modern electronics. Stuart’s work built on the discoveries of Albert Fert and Peter Grunberg in giant magnetoresistance (GMR), for which they received the Nobel Prize in 2007. Stuart and his IBM colleagues invented the spin valve head, based on GMR, and IBM used their invention to bring massive improvements to the storage capacity of disk drives.
In recent years, Stuart grew frustrated with the limits of two-dimensional structures in both disk drives and integrated circuits. “All these technologies live in flat land, which doesn’t make sense since the world itself is three dimensional,” Stuart says. So he’s been working on materials and structures that will enable three-dimensional computing–which will overcome the limits of today’s tiny electronic devices and make possible tremendous gains in storage and computation.
The most notable of his forays was his invention in 2004 of racetrack memory, which applies spintronics to nanowire tracks positioned above the surface of a chip. The data is stored as magnetic regions on the tracks and is propelled along the wires at lightening speed by the spin of electrons. Racetrack memory promises to pack 100 times more data in the same space as either a hard disk drive or a traditional memory chip at a much lower cost than either–while using much less energy. If and when racetrack memory is commercialized, it could represent a major advance affecting every aspect of IBM’s Smarter Planet agenda, including sensors, networks, mobile devices, and data analytics. It could make it possible to store every movie made in a year on a single portable device.
But while Stuart continues to work on improvements to racetrack memory with his IBM Research colleagues, his bigger target is cognitive devices, which might take advantage of some of the science underlying racetrack memory.
He got started on this pursuit in 2008 when he was part of a team lead by IBM Researcher Dharmendra Modha, now an IBM Fellow, when the group launched the so-called SyNAPSE project. Funded by the US Defense Advance Research Projects Agency, SyNAPSE represents an ambitious effort to invent a new generation of chips and sensor-based computer systems modeled on the functions of the human brain. Originally, DARPA envisioned an entirely new chip technology based on new materials as well as new computing architectures. But the research team made of IBMers and scientists from five universities found that it would be impossible to come up with an entirely new chip technology on the aggressive schedule laid out by DARPA. So, instead, they designed a chip based on today’s silicon semiconductors. That team is on track to deliver on all of DARPA’s metrics on budget and ahead of schedule.
Meanwhile, Stuart is captivated by the idea of pushing forward with an effort to invent cognitive chips from the ground up. “My focus is on challenging problems that have a huge potential impact on people’s lives,” he says.
At the Max Planck Institute, which is funded by the German government, he will have complete freedom to take his research in any direction he likes and a staff of 40 to 50 technicians, engineers, scientists, visiting scholars and graduate students. He’s the opposite of the stereotypical scientific genius working in splendid isolation. Rather, “you want to have many people thinking about this problem,” he says. “You work with others and come up with concepts and new ideas and to test them experimentally.”
One of those others will be Claudia. When they met, he was skeptical about the ability of scientists to control the placement of atoms on surfaces with the precision needed to change the characteristics of the Heusler materials. She has convinced him otherwise. Once at odds, they’re now in sync.
This could mean the continuation of a beautiful friendship.