Liam Barron is currently an undergraduate student at Vanderbilt University. He is pursuing a bachelor’s degree in trombone performance and applied mathematics.
You work in Professor Kálmán Varga’s group at the university. How did you get in touch?
Liam Barron: Unlike most researchers in Varga’s group, I did not major or minor in physics. In high school, I primarily studied mathematics, computer science, and music. I met Sam in the Blair Big Band and he introduced me to Dr. Varga. Since the nature of his research is primarily computational simulations, the group was a particularly good fit for my skill set.
What did you know about Hungary, Szeged and ELI ALPS before?
I am a trombonist, and Szeged is home to the Szeged Trombone Ensemble, but outside of that, I knew very little about the city. Prior to coming, I had heard of ELI ALPS, as it is regarded as one of the top research facilities in the field, but again, I didn’t know much about it. Of course, having been at ELI ALPS researching for over two months now, I’ve found that it is a truly special place with amazing facilities and some of the best researchers and colleagues in the world. Professor Varga was well aware of what a great opportunity doing research at ELI ALPS would be for our group. When he informed us where we would be studying, we researched the city and the facilities and couldn’t help but be excited by the prospect. Similarly, Szeged has quickly become one of my favorite cities in Europe. I hope to have the opportunity to come back again in the future.
Sam Taylor and Liam Barron
Could ELI ALPS be more attractive to American students, young physicists, with the Nobel Prize in Physics awarded last year for attosecond science?
Certainly, this will make ELI ALPS a more attractive place for young students. The Nobel Prize in Physics is great because it allows us to recognize the outcome of the hard work of the individual researchers. However, it also helps capture the imagination of young scientists and inspires them to explore these fields. With last year’s award, ELI ALPS is uniquely positioned to be the perfect place for students to study attosecond science.
There are many avenues to physics research. Modern physics breakthroughs, especially in technologically advanced fields like attosecond science, are extremely interdisciplinary, requiring physicists and chemists, of course, but also engineers and computer scientists who can help build the equipment required for the experiments and process the data. I would argue that physics research benefits immensely from its interdisciplinary nature.
Samuel Taylor, physics and math student at Vanderbilt University, and undergraduate research assistant.
What has been your experience over the last two months?
Samuel Taylor: Over the past two months at ELI ALPS, my experience has been incredibly positive and enriching. The colleagues I’ve worked with have been extremely welcoming and supportive, and they have allowed me to conduct truly impactful research.
The institute itself is highly impressive, equipped with state-of-the-art facilities and technology. As a theorist, coming to ELI was my first experience visiting a lab. I have spent hundreds of hours studying Coulomb explosion, so getting to witness a live experiment and see the plasma with my own eyes was a feeling like no other. I cannot put into words how amazing it was to see something that I have gotten to know so well but have never seen in person!
Regarding my travel outside of work, I have had opportunities to go on trips around Hungary, Slovakia, and even to ELI Beamlines in Prague! Visiting ELI Beamlines was a wonderful experience. The scientists were incredibly friendly and let me and the other American students visit the labs. It was great to see how tightly knit the ELI community is.
It is said that theoretical physicists only need a pencil, a piece of paper and an eraser. Or do you need a supercomputer too?
Definitely a supercomputer! My work involves developing and running sophisticated computational models to explore and understand phenomena of different experiments (such as Coulomb explosion or molecule–molecule collisions) by simulating it on a computer. My research group back home (Varga’s group) uses time-dependent density functional theory (TDDFT) in order to create our simulations, and these simulations can be very computationally intensive. Therefore, we use the ACES supercomputer at Texas A&M University to run hundreds of simulations at a time and generate massive amounts of data (1 TB+ for my simulations alone).
Are Vanderbilt University students expected to conduct independent research?
Yes! One of the requirements to get the physics degree at Vanderbilt is to conduct at least three credit hours of undergraduate research. I started research in my freshman year and am continuing it now into my senior year.
In Szeged you were working on a theoretical physics problem. Did you pursue your American topic, or did you join a research project in Szeged?
Actually, when I was at home, I explored the same physics topic – TDDFT simulations of Coulomb explosion and molecule collisions – and was collaborating with scientists at ELI during the school year. I had online meetings with the experimentalists here at ELI every few weeks to discuss ideas, results, and what simulations they needed me to run to model their experiments.
What were the results?
My research here in collaboration with the scientists at ELI has led to several new interesting results. My simulations were able to accurately predict the distribution of fragment products resulting from Coulomb explosion and aligned with the experimental data. The simulations and experiments provided powerful evidence that neutral species can be produced through the Coulomb explosion mechanism.
Could there be a continuation of these two months?
Even though I return to the US in early August, I plan to continue my collaboration with the scientists here at ELI. Just as I did last year, I can meet virtually and work on projects with them. I have loved my time here and am extremely grateful for this opportunity!
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Coulomb explosion
A Coulomb explosion begins when an intense electric field (often from a laser) excites the valence electrons in a solid, ejecting them from the system and leaving behind positively charged ions. The chemical bonds holding the solid together are weakened by the loss of the electrons, enabling the Coulomb repulsion between the ions to overcome them. The result is an explosion of ions and electrons – a plasma.