David Larbalestier: When Curiosity Makes a Career

By Amy Mast

Magnet Lab Applied Superconductivity Center Director David Larbalestier is viewed by many of his peers as the leading researcher in the United States, and possibly the world, in the basic research of practical superconducting materials for magnets and power applications. Over a 35-year career, he has profoundly influenced the development of high-field magnets for high-energy physics and other applications, such as magnetic resonance imaging. Among the highlights of his career is his election in 2003 to the prestigious National Academy of Engineering.

Most of us get frustrated when faced with a question we can't answer. We'll pass it off to someone else, come back to it later, or abandon it altogether.

David Larbalestier, however, has made a career of tackling questions that may not be answered in his lifetime, if ever. Those questions – all related to the phenomenon of superconductivity – have energized a generation of researchers, because knowing the answers could transform how the world delivers and stores power.

Larbalestier directs the Magnet Lab's Applied Superconductivity Center (ASC), where he has assembled a team from senior scientists on down to graduate and even undergraduate students to look at superconductors from every vantage point. Superconductors are materials that conduct electricity with no resistance. Electricity comes from electrons traveling through wire conductors.

Those electrons bumping into each other generate an enormous amount of heat. With superconductors, however, there is no jostling, therefore no heat. But there's a catch: superconductors only behave this way when they are cooled to very low temperatures. The ASC, among other things, hopes to develop materials that super-conduct at higher temperatures, with the "holy grail" of achieving superconductivity at room temperature.

The ASC functions as a division within the Magnet Lab. The group, including senior colleagues Eric Hellstrom, Alex Gurevich, Peter Lee and Bill Starch, moved to Tallahassee along with Larbalestier from the University of Wisconsin around two years ago, with virtually all of the Center's 20-strong team intact. It's a group Larbalestier, 65, has built up over a 35-year career as a researcher and professor – a career that could have easily been in politics or the humanities. He came of age, after all, in the 1960s.

Bouncing Between Arts and Sciences

The son of a Royal Air Force pilot who'd left school at 14, Larbalestier was born in 1943 and grew up in postwar London, a city gravely damaged by World War II.

"During that time," he explained, "life was pretty constricted, and around me was this idea that education was valuable because, frankly, you just got a better life."

The postwar British educational system immersed its students in a rigorous, classical program of studies, and Larbalestier navigated the UK's equivalent of high school with a focus on the humanities (particularly language) rather than the sciences. The complex systems he discovered in his science classes, however, soon had as much appeal for him as the complex systems he'd enjoyed studying in language, and at 16, he turned down a humanities-track undergraduate spot at Cambridge, one of the country's elite institutions.

"People wanted me to go on in a humanities vein, but I began to try and force myself onto a scientific track. Although I didn't want to go back to ancient languages, I found myself more and more interested in political, moral and societal questions than anything else. It took me a while to settle down into anything."

Larbalestier settled on a scientific-track at Imperial College in London, also an elite institution. His enrollment coincided with the explosion of music, arts and culture that was London in the 1960s, and he immersed himself in it. "I spent far too much of my undergraduate career involved in political matters and in music particularly," he said with a smile. "I think it was only in my senior year that I really turned on to my work and I became determined to go and get a Ph.D."

He earned a degree in Physical Metallurgy in 1965, and chose to conduct his graduate work at the same institution.

Superconductivity Catches Fire

In 1964-1965, during Larbalestier's last year of undergraduate study, superconductivity was just emerging into public view, based on the possibilities unlocked by the 1962 discovery at Bell Labs of high magnetic field superconductivity in what very quickly became viable superconducting wires of Niobium compounds and alloys. These possibilities were energizing researchers everywhere.

During Larbalestier first year of graduate school, his adviser, who studied the properties of alloys (marriages of metals make much better superconductors than pure elements), was hooked. "In that first year of graduate school, superconductivity transformed from this very interesting and more conceptual physics problem to something entirely new," said Larbalestier. "People went wild with the practical possibilities."

The phenomenon of levitation, now a commonplace demonstration of superconductivity's properties, proved irresistible for Larbalestier. "For me, in those days of course the levitation only existed as a picture in a book, but (seeing) it was amazing. I've never lost my enthusiasm for that."

Though he worked dutifully during graduate school, he found himself unexpectedly bored with the day-in, day-out process of obtaining data. During his project, his adviser left for an 18-month sabbatical in Berkeley, California, and except for the occasional letter, Larbalestier was on his own. His work, he said, attracted little attention from his peers or superiors.

As he navigated his project by himself, Larbalestier began to notice that something was amiss. The magnet he used for his superconductivity experiments gave inconsistent readings, and this inexplicable variation stymied his experiments and caused him to grow increasingly frustrated.

Once Larbalestier discovered the problem, it changed both the direction of his graduate work and his attitude toward his chosen career path. He discovered that the magnet he'd been using for his experiments was made partly of a particular grade of stainless steel, one that became more and more magnetic with each exposure to magnetic fields.

"I began to focus more on the magnetic transformations in the stainless steel, and I found it very exciting. Frankly, I was bored stiff with the superconducting part of what was in my thesis," Larbalestier said with a laugh.

What was a potentially catastrophic and expensive mistake in magnet construction became both a learning opportunity and a chance for Larbalestier to take his thesis in a direction he found more promising. Armed with his new knowledge, he went to an Institute of Metals meeting in London, only to find a group of engineers at the British High Energy Physics lab (Rutherford Lab) planning to build an eight-tesla (powerful by the standards of the late 1960s) superconducting magnet swathed in the same stainless steel that had corrupted his experimental results.

Larbalestier had come prepared to speak on that very topic. "I got up and gave my little talk, probably very timid, and the guys said, 'My God, we've got to talk.' That started a relationship with the high-energy-physics community that has been absolutely continuous. They have been wonderful supporters for me and we've been deeply involved ever since," he said.

That intersection of two projects – one by a group of ambitious researchers, the other by a lone, disaffected graduate student – was one moment in many combinations of diligence and serendipity that have served Larbalestier well.

"My whole career has been sort of a lovely random walk, a response to opportunities that presented themselves at various points in time. If you're presented with several options and without fail choose the more difficult one, you will be rewarded for it," he noted.

Blending Research, Teaching

By the mid-1970s, with his thesis and subsequent postdoctoral work in Geneva and London complete, Larbalestier, his wife Karen, and their children moved to Madison, Wisconsin, where he began a 30-year span as an educator and researcher, building a tight community of scientists and technicians around his work that has followed him to Tallahassee.

"Even now, there's a transformational aspect to superconductivity, a wonder, and around you forms a kind of culture of people who are just trying to do things that haven't been done before," he said.

As the years passed, his star rose in Madison, and awards, honors, and positions of greater responsibility followed. In 1981 he was named the associate chairman of Wisconsin's department of Materials Science and Engineering. In 1989, he was named director of the NSF-supported Materials Research Group in High Temperature Superconductivity, and in 1991 he was made a full professor and the director of Wisconsin Applied Superconductivity Center.

All the while, Larbalestier was beginning to appreciate what for him was becoming an increasingly important relationship between his research and his teaching.

"What I realized is that you had this wonderful ability to take freshmen and sophomores while they were still open to this idea that education could be transformational. Then you could challenge them, get some of them to come and work in the lab and do really significant stuff while they were still undergraduates, and you know, some of these guys stayed with me. Others went on to Stanford or Berkeley or MIT. The light went on for them and it was: 'Yes, education is transformational and it's exciting' and essentially all I had to do was provide a culture and an opportunity for people like that, and they do wonderful things."

In the winter of 1983, materials scientist Peter Lee, still a principal investigator on the ASC team, joined Larbalestier. Lee echoes Larbalestier's focus on blending research with educating the next generation of scientists, calling the most important accomplishment of the team "David's 31 Ph.D. graduates."

"David has a remarkable depth of understanding across the broad range of scientific disciplines that are needed in combination to make advances in the practical application of superconductors," said Lee. "It does not hurt that he is very, very, smart but combining that with his leadership and personnel skills make it both an honor and a pleasure to work in the group." Peter Lee added to David's capabilities in many essential ways, primarily by advanced electron microscopy and together they worked out many of the essential keys to pushing today's most practical superconductors, to their limits. In 1987, superconductivity at liquid nitrogen temperatures was discovered.

Eric Hellstrom was a newly hired assistant professor of ceramics and joined in to make and understand these still hotly studied and not yet understood materials. In the early 1990s, Alex Gurevich joined too, bringing a quite unique expertise in condensed matter theory and strong interests in applications of superconductors.

The Move to the Mag Lab

Though the Magnet Lab had offered once before, Larbalestier and his colleagues at the Applied Superconductivity Center didn't make the move from Wisconsin to Tallahassee until two years ago, when they felt that such a move would be compelling to both ASC and the Magnet Lab.

Pointing out that he is later in his career than his colleagues, Larbalestier was gratified that the lab agreed to move all of ASC rather than a handful of "starter" personnel.

"The wonderful thing about this new location is that the synergy is clearly here. You can see that superconducting magnets made of the high-Tc ceramics can become the next big thing. We've had amazing discoveries in the past six months. It's been an exciting time, even if for some of the younger people, a stressful one," he said.

At FSU, Larbalestier is still teaching for a semester each year – this term, a mechanical engineering class. He admits that engaging students in his field can be difficult and laments that in his current class of 40, there are no female and few minority students. Somehow, he says, interest in science and engineering is diminishing and narrowing, just at a time when the grand challenges of the world demand a much broader technical understanding of our highly connected and interdependent world.

"I think I was very well educated in the following sense – virtually all the teachers I had were interested in what they were teaching, and they wanted to pass on that interest. Students need to be persuaded to demand a lot of themselves so that their horizons expand, and not shrink in the crucial 5 to 10 years after graduation, when self teaching is the principal route to keeping fresh and up to date."

FSU, he says, is a "university with aspirations," a place where he feels that both lab and university leadership are willing to pursue meaningful, wide-ranging projects.

"This is an open, exciting culture that is actively trying to get more and more people to come and use the facilities and to collaborate. It's a very enviable environment," he noted.

And what of the original question, the superconductivity answer Larbalestier and his team have been chasing all these decades? Will he mind if a room-temperature superconductor is discovered long after he and his team are gone?

"If this discovery takes place, it is going to happen by accident, or it's going to happen by a stubborn and very individual act of invention on the part of one or two people," he said. "I'd love to see that, but on another level, I wouldn't mind if I don't, because I think the very complexity of life is one of the things that, looking back on life, is an opportunity for wonder."

---