People

Duncan Stewart

E-mail: duncan.stewart@hp.com

Location:
Quantum Structures Research Initiative Department
Hewlett-Packard Laboratories
Palo Alto, California

Biography:
Duncan Stewart sees himself as midway between a physicist and an engineer. And that's exactly how he likes it.

His team in the Quantum Science Research group is sort of a hybrid as well -- a mix of chemists, physicists, engineers and a computer architect -- and he likes that, too.

"Most of the great advances in the future will come by combining different fields of science," he says. "It's only by mixing together different ways of looking at things that we really are going to make significant progress."

Stewart, whose holds a PhD in engineering physics, is the Quantum Science Research team's electronics tester. His job is to measure and understand how electricity passes through the molecular circuits.

"My role is to determine what the thing is actually doing, and then try to figure out why it's doing that," he says. "The devices we're building behave in strange and wonderful ways, and the truth is, we understand very little of that."

The goal: to understand the devices well enough so that they can be controlled and mass produced. That's an incredibly complex problem.

"At the very tiny sizes we're working with -- we're talking 20 or 30 atoms in one row -- it's very difficult to know whether those atoms are in a straight line or crooked line, or if there's another atom that found its way into there by mistake," he says. "It's difficult to go in and characterize what we made and to learn what is inside there."

Stewart uses several investigation techniques -- measuring how devices behave when different voltages are applied, or when the frequency of the electricity is changed, or when the temperature changes, to name a few -- but none paints a full picture. At this stage, the best he and his colleagues can do is put all of the evidence together and guess.

Despite the team's recent success -- creating the highest-density electronically addressable memory known to date -- the solution is still a long way off.

"This particular demonstration is one successful milestone on a long and torturous path that we hope leads to success," Stewart says.

He finds the work rewarding nonetheless, in part because of the blend of people and talent that go into achieving those milestones.

"Each one of these devices is touched by at least three people, usually four or five, and each of us contributes what we're best at. And it works," he says. "The finished product was better than any one of us could have built."

He joined the QSR group at HP Labs in September 1999.

Education:
B.A.Sc. in Engineering Physics from the University of Toronto in 1992 Ph.D. in Applied Physics from Stanford University in 1999

Hobbies:
Wilderness trekking, sailing, travel

Biggest influence:
My parents as role models, my experiences traveling the world

Links:
Molecular electronics team - a scientific melting pot