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Chemist's Job: Hunt Down the Smallest, Fastest Particles

Stephen Leone in his laser laboratory at Lawrence Berkeley National Laboratory.
(Image: © Roy Kaltschmidt, Lawrence Berkeley National Laboratory)

This ScienceLives article was provided to LiveScience in partnership with the National Science Foundation.

Small, smaller, smallest. Fast, faster, fastest. These appear to be the watchwords for today’s technology. Moreover, they guide research for tomorrow’s technology and University of California, Berkeley, chemist and physicist Stephen Leone helps lead the way. He works with the smallest and fastest particles ever observed. For the first time, he and an international team of scientists used ultrashort flashes of laser light to directly observe an atom’s outer electrons. Through a process called attosecond absorption spectroscopy, his team was able to time, with great precision, the repetitive variations between electrons that simultaneously produce quantum states. The outermost electrons of an atom are crucial for deciding how an atom will react chemically with other atoms. Attosecond transient absorption will, in Leone's words, "allow us to unravel processes within and among atoms, molecules and crystals on the electronic timescale" – processes that previously could only be hinted at with studies. Read more about Leone’s work here, and his responses to the ScienceLives 10 Questions below.

Name: Stephen Leone Age: 62 Institution: University of California, Berkeley, and Lawrence Berkeley National Laboratory Field of Study: Chemistry and Physics

What inspired you to choose this field of study? I always did well in chemistry, physics, and mathematics, and I enjoyed delving into how things worked. In high school I had the chance to accelerate my studies independently, with the amazing help of some foresighted teachers in my small town. My older brother was studying for a Ph.D. in chemistry, and at the same time I had a great opportunity to skip several general chemistry classes as an undergraduate at Northwestern and take the organic chemistry sequence. The professor, Joseph Lambert, was excellent and very modern. I think this really was what sold me on chemistry as a field of study. The cohort of students that I hung around with at Northwestern was all real lab rats. We all joined research groups together, and Duward Shriver had a profound influence on my career by giving me an incredible opportunity to do some of the first-ever laser Raman spectroscopy experiments. There was no turning back for me. I was going to be a laser person, somewhere between the fields of chemistry and physics.

What is the best piece of advice you ever received? You have to have some "bread and butter" along with the "pie in the sky" (Gerald Segal, USC). My group always tried to emphasize large, detailed and rigorous papers. When something we did was high profile, we recognized it as such, but we did not go out of our way to only emphasize the pie in the sky. This philosophy served the test of time and trained many students to be great scientists. I would do it the same way again.

What was your first scientific experiment as a child? I had a small box of electric motors, magnets, variable resistors and components from my dad that I was always taking apart and figuring out how they worked. A chemistry set as a gift led to my first real experiments – and the whole house smelled of sulfur.

What is your favorite thing about being a researcher? Watching my students mature as scientists, i.e. going from amorphous enthusiasm to becoming knowledgeable scientists, accomplishing amazing things on their own – often starting from ridiculously hard suggestions of what to do from me and going off and starting their own careers. I often think it is not the data that will be my legacy. It is the human successes I have had in helping graduate students, postdocs, undergraduates and visitors achieve their goals.

What is the most important characteristic a researcher must demonstrate in order to be an effective researcher? Learning to be circumspect, not jumping to conclusions, thinking up possible alternative explanations, and one by one eliminating them.

What are the societal benefits of your research? Developing technological tools that stretch the limits of imagination and the abilities to measure new things.

Who has had the most influence on your thinking as a researcher? Carl Lineberger, the very best colleague, friend, hero and role model! His wisdom, often provided in nontransparent Linebergerisms that seemingly confound the mind, is priceless. Carl once told me that when I do an experiment, I know where every dial and knob should be turned, and what the outcome might look like if it is going to make physical sense. He was right.

What about your field or being a researcher do you think would surprise people the most? Everyone would figure out that my group reinvents itself regularly. Some would say my mentoring about getting grants is legendary. That would be no surprise. What would be surprising is that my studies of vibrational energy transfer as a student with Brad Moore played such a large role in how I approach problems and analyze solutions today. There is an intuition about experiments that I acquired, and people would be surprised that what I learned in those formative years has so much to do with how I approach attosecond electron and wave packet dynamics and other problems now.

If you could only rescue one thing from your burning office or lab, what would it be? My wife, Mary Gilles, if she were there with me. Otherwise, the photo albums containing the pictures of all my students, postdocs and visitors.

What music do you play most often in your lab or car? Never in the lab, because one will not hear the pump that is about to fail. In the car it is classical that is calming for me. Beethoven, Mozart...

Editor's Note: This research was supported by the National Science Foundation (NSF), the federal agency charged with funding basic research and education across all fields of science and engineering. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author and do not necessarily reflect the views of the National Science Foundation. See the ScienceLives archive.