Neurons that can multitask greatly enhance the brain’s computational power, study finds.
(Robert J. Birgeneau is dean of the School of Science. He is also the Cecil and Ida Green Professor of Physics. The following excerpts from a faculty profile interview by Dorothy Fleischer are reprinted from RLE currents [spring 1994] with permission from MIT's Research Laboratory of Electronics.)
Fleischer: What motivated you to work in the field of solid-state physics?
Birgeneau: In 1963, I had just finished as an undergraduate in mathematics at the University of Toronto. My first thoughts were to go to MIT to attend the Sloan School and do operations research under Professor Jay Forrester. That summer, I had a job at Chalk River Labs in Ontario, Canada, where what became known as the field of neutron scattering was pioneered. The group at Chalk River was interested in studies of lattice dynamics or acoustic vibrations in metals. I worked with another student, John Cordes, who is now a professor at Dalhousie University. The lab wanted to begin a program on transition metals, so it was a good project for the two of us.
As circumstances would have it, the scientists in charge had to go away for most of the summer. John and I spent the first month reading a graduate-level textbook and teaching ourselves solid-state physics. We spent the rest of the summer measuring the lattice dynamics in nickel metal. We performed and completed all the experiments correctly and did most of the analysis ourselves. When our mentor Gerald Dolling returned, he congratulated us on our efforts, and then we produced a draft of a paper that was subsequently published in the Physical Review. I think it's still my most referenced paper!
That job essentially taught me solid-state physics, which I thought was rather exciting research with a good combination of experiment and theory. It also made me realize that I enjoyed doing research and I might even have a talent for it. Based on that, I decided to go to graduate school in physics at Yale.
Fleischer: What brought you to MIT?
Birgeneau: [After graduate school] I worked at Bell Labs for almost eight years and really enjoyed it, but I was interested in education and working with graduate students. At Bell, if you had "human" talents, there was tremendous pressure to go into management. If I stayed, I'd ultimately be pursuing an administrative career. That was the last thing I wanted to do at that time, even though I had just become the research head of the Scattering and Low Energy Physics Department. I wanted to do undirected basic research as long as I could, and I knew it would be easier to do so in a university environment.
One possible option seemed to be Harvard. I discussed this with Werner Wolf at Yale, and he said, "When you think about where you want to end up, remember one thing: at MIT, science and engineering will always matter." Fortunately, Peter Wolff, who had hired me at Bell, was now on the MIT faculty and responsible for building up an effort in solid-state physics. Since he had hired me before, and I wasn't a total failure, he hired me again at MIT.
I must say that my expectations, in terms of the graduate students at MIT, have been surpassed. I have had many outstanding students here who have gone on to very successful careers in universities, industry, and national laboratories.
Fleischer: What has been the progress of your work in RLE?
Birgeneau: When I came to MIT in 1975, I wanted a lab where the students could do preliminary experiments, and then at some point, go off to do experiments at national facilities, such as those at Brookhaven. I decided to try something new to diversify my research, so I planned a program in x-ray scattering. Previously, there had been x-ray diffraction research for its own sake at MIT.but our approach was rather different. We were less interested in characterizing x-rays and their interactions with matter and more focused on using them as tools to elucidate new kinds of physics.
In some ways, my RLE research has probably been the most creative work that I've done at MIT. It was about 1970 when Dave Litster started a research program in liquid crystals [Ed. Note: Professor Litster is now Vice President and Dean for Research]. Few experiments had been done in that field using x-ray techniques, and it seemed that the experiments could be done much better than what had appeared in the literature. Dave came to me with some very creative ideas on using x-rays to study liquid crystal [materials]. I quickly educated myself on the science of liquid crystals, and we began a new research direction in RLE. We were joined by an outstanding Danish physicist, Jens Als-Nielsen. By synthesizing and integrating information from our individual experiments, we were able to make significant progress in understanding the nature of liquid crystals.
Our next major research program with x-rays, which has probably had the most long-standing impact, was work that started in 1978 with Paul Horn, then with the University of Chicago. At that time, people at Brookhaven were using neutrons to characterize the properties of single layers of rare gas atoms on graphite. I studied that work and realized that x-rays could do a better job. Under the sponsorship of the Joint Services Electronics Program in RLE, we looked at the physics of single layers of rare gases adsorbed onto graphite. It turned out to be a novel and rich area of research that contained much of the basic physics important in a variety of surface problems. Furthermore, through [Institute Professor] Millie Dresselhaus, we learned that much of this physics could be applied directly to intercalated graphite materials. This led to a series of experiments by myself, Millie and Simon Mochrie (associate professor of physics) elucidating some very novel phase transitions in two dimensions.
In the course of the rare gas monolayer studies, Paul Horn and I talked with David Moncton of Bell Labs who was an MIT graduate. Dave realized that we could do much better by using x-rays emitted by large particle physics machines. We worked together at the Stanford Synchrotron Radiation Laboratory, exploring the use of synchrotron radiation to study condensed matter and emphasizing the physics of single layers of rare gas atoms adsorbed on graphite. It turned out that the synchrotron's geometrical characteristics were quite favorably matched to study surface physics as well as other problems such as thin films of liquid crystals. We were able to analyze the data quantitatively in a way that is still not possible with traditional surface probes.
Horn, Moncton, and I got to play a seminal role in developing synchrotron radiation techniques for high-resolution condensed matter studies. These techniques eventually made possible research we hadn't even anticipated. Today, this field is a multibillion-dollar worldwide endeavor that had its roots in the early experiments carried out at Stanford by our group and, of course, many others.
In terms of its impact on science, our early role in helping to develop the field of high-resolution synchrotron x-ray scattering may well be the single most important achievement in all three of our careers.
Fleischer: Is there a project that you're particularly excited about today?
Birgeneau: We accidentally discovered in some of our experiments that, at high temperatures, the structures and phase transitions of silicon surfaces depend on how we heat them. At first, we found this to be an annoyance, but we now realize there is some important and deep physics happening here. Under the Joint Services Electronics Program in RLE, we are probing the behavior of semiconductor surfaces at high temperatures. It may potentially have great practical importance because, by properly combining electric field and temperature conditions, we can manipulate the morphology of the surface at both the microscopic and macroscopic levels, determine what the surface looks like, and then, by quenching, we can retain that structure at room temperature.
Fleischer: What has been the most challenging problem in your field?
Birgeneau: The most difficult physics problem that I continue to work on, in addition to the surface issues I have mentioned, is to understand the basic microscopic physics of high-temperature superconductors. It has been an extraordinarily deep and difficult problem whose immensity Marc Kastner and I really could not have imagined when we started our collaboration in 1987. [Ed. Note: Dr. Kastner is the Donner Professor of Physics.] At that time, I thought it would be a two- or three-year research program, and that was clearly a gross underestimation. High-temperature superconductivity is a deep phenomenon that, when solved, will probably have an impact that goes far beyond the copper oxide materials themselves.
Fleischer: What are your thoughts on university-industry collaborations?
Birgeneau: We take pride in this area, particularly since we've had such a successful, long-term connection with IBM. Although they're going through a difficult period, IBM has nevertheless made a commitment of several scientists as well as equipment funds to join us and McGill University in our x-ray beam line project at Argonne.
More generally, in this era, I believe that university groups such as mine must fill in the gaps in "strategic" basic research that currently is being curtailed by industry. Hopefully, in turn, our technologically sophisticated industries will also support us in that endeavor.
Fleischer: Do you have a vision for the School of Science?
Birgeneau: Yes and no. No, simply because I do not know what will be the most important issue in the year 2010. The yes has several aspects to it. The dean of science has a special responsibility to ensure that MIT maintains its excellence in basic science research and education. At the end of World War II, MIT was an outstanding institution in engineering, but it was not yet a leader in science. Our science leadership has built up progressively over the last fifty years. Indeed, we are now probably the leading school of science in the United States, at least according to US News and World Report. It's the dean's responsibility to be aware of emerging fundamental issues in science and to make certain that the school is organized in such a way that it can have a significant impact. The frontiers of science are constantly evolving, and we must make certain that we stay at the cutting edge.
Similarly, science is at the core of the educational process at MIT. As dean, I have tried to impress upon the department heads and the faculty the importance of education, both undergraduate and graduate, in the classroom and in the laboratory. I have made certain that excellence in education is recognized in both our salary structure and promotion process. Also, we are continuously encouraging experimentation in education. Our salient achievement in undergraduate education has been the introduction of biology into the core curriculum.
In terms of a vision, there are so many important issues, and because of the size of the School of Science, we have many opportunities to make a major impact. As Dean of Science, the major initiative that I've been involved in is bringing the neurosciences to the School of Science. The Department of Brain and Cognitive Sciences has moved into the school, and in May we announced the formation of the new Center for Learning and Memory. I am very proud of that. Eventually, I hope to see MIT evolve from a university that does valuable work in brain and cognitive science to the leading center of neuroscience research in the US It's an emerging field with remarkable opportunities, and I believe that MIT is well placed for the next several decades in this exciting arena.
We have also tried to create a nurturing environment for young people on our faculty so they can do great things. As head of the physics department and then as dean, I've put a lot of energy into attracting and supporting outstanding young scientists. Ninety percent of the faculty we hire are beginning assistant professors. In my first year as dean, I changed the salary structure in the School of Science so that our junior faculty are now the second highest paid in the country. We also provide young people with generous start-up packages that enable them to establish their research programs quickly. As part of this, we are trying very hard to increase the diversity of our faculty so that they properly reflect the makeup of the student body and the nation that we serve.
Fleischer: Do you have a secret to your success?
Birgeneau: To the extent that I've had success, there are probably three things in addition to simply working very hard. First, I truly enjoy what I'm doing. Second, I've always kept my eyes firmly fixed on fundamental issues in science. And third, I've tried hard to be impeccably honest in my research and not to be swayed by this year's fashion.
Fleischer: Do you have advice for young people?
Birgeneau: Do not do basic science as a means to an end, do it because you really love it. There are easier ways to make a living that are less competitive and less difficult. If you choose a career in science, choose it almost like you'd choose a religion. Also, be prepared to work extremely hard. Science isn't a nine-to-five job. In terms of what our junior faculty members achieve, I clearly see the difference between those who work on weekends and those who do not. When you enter a university environment, you should come not only because of the research, but also because you want to play a role in educating the next generation. At MIT, education matters. Finally, one must always have the courage to try completely new and outrageous things. They are inevitably the most exciting and have the biggest reward.
A version of this article appeared in the September 28, 1994 issue of MIT Tech Talk (Volume 39, Number 6).