For Chancellor Birgeneau, research is for life

Chancellor Birgeneau’s job leading the campus is all-consuming, but he still finds time for his first love: research. Recently, he was given the prestigious 2012 Cliff Shull Prize by the Neutron Scattering Society of America, a lifetime achievement award “for his seminal scientific contributions, tireless leadership, and devoted mentoring in the field of neutron scattering.” In an interview at his office, the chancellor talked about juggling the chancellorship and staying on the cutting edge of physics research.

UC Berkeley Chancellor Robert Birgeneau.

UC Berkeley Chancellor Robert Birgeneau.

Bruce Gaulin, the society’s president, said it is “remarkable…that the chancellor has maintained a vibrant research program while being chancellor at UC Berkeley.

“This is very uncommon. University chancellors have their dance cards full – their time is fully accounted for, and it’s very hard to…carry on research at a high level while also carrying out these important responsibilities. It clearly speaks volumes to how important science is to Dr. Birgeneau. He is not willing to let it drop.”

Q: In spite of a very busy schedule, you find the time to explore the physics of exotic materials like high-temperature superconductors. Why is it important for you to do research?

A: There are some people who think being a chancellor should be a full-time job.  Frankly, when I came here, I didn’t realize fully how important it would be for me to have a parallel life as a faculty member, just to do my chancellor’s job better. It’s a psychological need, and also for my daily enjoyment.

Q: How do you find the time?

A: On weekends. A few hours on Saturdays and Sundays. I may go over to Birge Hall, the physics building, but mostly my students come here, or we email back and forth. I spend a lot of time on airplanes reading physics articles.

Once in a while, I get a cancellation, and I’ll be thinking about a physics issue, so I’ll immediately email one of my post-docs and say, “Hey, why don’t you come over? I want to talk with you about something.”

Q: How many students do you have in your lab?

I have one graduate student and four post-docs. Until two years ago, I always had a number of undergraduates in my lab, which was quite enjoyable. It was a way of staying connected with undergraduate students. Since we started working on arsenic-based materials, however, because of safety considerations, I no longer can have undergraduates in my lab, which I greatly regret.

My research effort is split between the campus, where I have a materials characterization lab in the physics department, and LBNL (Lawrence Berkeley National Laboratory), where the materials preparation is done in partnership with an excellent senior scientist by the name of Edith Bourret. My research would not be possible if it wasn’t for her support.

Q: What work of yours is the Neutron Scattering Society of America recognizing?

It’s actually more of a career award. In trying to understand these exotic materials, it turns out that using beams of neutrons from either accelerators or nuclear reactors is particularly important. I have a longtime investment in the basic science in this field, plus have chaired DOE (Department of Energy) committees that assessed both the field and the facilities that are available nationally and internationally. So, the award also recognizes the leadership that I provided on the administrative side.  In addition, the award recognizes my success in graduate student mentoring.  Former students of mine are now professors at Harvard, MIT, Yale, UC Santa Barbara, Cambridge and many other leading universities nationally and internationally.

Q: The award, the Clifford G. Shull Prize in Neutron Science, is named after a friend of yours?

This award is very special for me because Clifford Shull was the founder of our field and a former colleague (at MIT). He was just a wonderful, creative scientist, and quite modest and soft-spoken. He was the kind of person who was in the lab himself every single day. I had  nominated him for the Nobel Prize, so when he won it in 1994, I was overjoyed.

Two types of high-temperature superconductors.

Exotic new high-temperature superconductors grown in Birgeneau’s laboratory. The one at left is made of iron, tellurium and selenium. At right is a single crystal of a newly discovered iron-based high-temperature superconductor called K0.8Fe1.6Se2. Photos by Jun Zhao and Jinsheng Wen, UC Berkeley.

I work on highly correlated electronic systems. Let me give you a human analogy to the electrons in these systems: You’re walking through a crowd, and you’re trying to figure out what pathway you’re going to follow. If you were uncorrelated to everybody around you, you would follow whatever pathway was most convenient for you.  In a correlated system, however, your next step is determined completely and entirely by the steps of the people immediately around you. So, you don’t act as an independent agent in a crowd, but rather, the options available to you are strongly influenced by the people around you, who, in turn, are strongly influenced by the people next to them.

This means that whether the system is magnetic or non-magnetic, whether it’s an insulator, a normal metal or a superconductor, depends completely on the cooperative behavior of the electrons in it. In addition, the materials I study are quantum systems: The energy states are determined by the laws of quantum mechanics.

There is currently no mathematical structure available that is powerful enough to describe such systems from first principles and to be able to predict properties of new materials. This means that experiments are anomalously important.

Q: What’s an example of a practical application of your basic research?

Liquid crystal displays, or LCDs. Every time you turn on your computer or your (flat screen) television set with an LCD screen, you owe physicists and chemists in my field. People in our field had to develop new materials for our basic research; these materials, which are quite robust, have turned out to be the materials that underlie the display industry.

A really important aspect of knowledge-driven basic science, especially for experimentalists, is that you always have to develop technologies to do your experiments better, and it’s often the technologies you develop rather than the questions you are asking which end up producing important applications.

Q: What kinds of experiments do you do?

Our goal is to identify materials that have unusually interesting properties, such as high-temperature superconductors. The Shull Prize recognizes my use of neutron beams to probe the properties of these materials at the atomic level. The neutron beam scatters off the atoms collectively and tells us about the electron spins and the nuclear positions.

As I noted before, our aim isn’t for practical devices; it is to understand materials at the most fundamental level. When I began my research program here at Berkeley, we focused on traditional high-temperature superconductors, which are based on two-dimensional sheets of copper oxide. But I had a stroke of luck. In 2007 and 2008, a completely new and unexpected class of materials was discovered based on sheets of iron arsenide – iron plus arsenic. This was a boon for me because, when I switched to studying these materials, which have quite exotic properties, I was really starting up a new research program from scratch at Berkeley.  Instead of just continuing old lines of research going back to my MIT days, I had the opportunity to participate in a completely new field.

Now, we’re just working away at trying to characterize the materials and to elucidate the basic properties, so we know how to think about them. This field is at a very early stage of development, which is the most fun for me, my students and my postdocs.

Furnace for making new materials.

A travelling solvent floating zone furnace for growing single crystals. Birgeneau lab photo.

Q: What are you most known for?

A couple of my friends and I (at Bell Laboratories in New Jersey and Brookhaven Lab on Long Island) were among the very first experimentalists who figured out ways of accessing properties of matter that would exist in universes that were other than three-dimensional.  We did the first experiments on physical systems that were truly fractal – that behaved as if they existed in universes with non-integer dimensions, such as 2.67. We also did an experiment that proved directly that you cannot have ordered matter in a one-dimensional universe.  I was fortunate to have two great mentors, Werner Wolf, my thesis advisor at Yale, and Gen Shirane, my longtime collaborator at Brookhaven.

Q: How has doing research helped you as chancellor?

It has been quite helpful because I have had all the experiences of a new regular faculty member. There were no favors! It was torturous, actually, to get my lab started in the physics building, because, among other things,  I did not negotiate a start-up package when I decided to come here as chancellor. Who was going to pay for my lab and the equipment in it? I had to scrounge together money from many sources.

I think that experience was quite important, because, especially if you come in at the top as chancellor, you might have no idea about the challenges that individual new faculty members face. I got to experience every single one of them. Since then, we’ve made improvements on the research administrative side.

Q: Do you anticipate having a lab after you step down as chancellor?

I anticipate doing experiments myself when I step down as chancellor, instead of having just my students and postdocs do them. I anticipate a significant step up in my research activity, along with spending a considerable amount of time teaching and serving on national committees, the kind of public service in Washington I did a lot of before I became chancellor.

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