Superconducting materials, which can conduct electricity without resistance, are currently used in magnetic resonance imaging and have the potential to transform electric power generation, ultra-high speed supercomputers and particle detection technologies. While pursuing his Ph.D. in physics at Drexel University, Tomas Polakovic became fascinated by nanoscale strongly correlated systems, which are compounds used in insulators, electronic materials and superconductors. His research brought him to the U.S. Department of Energy’s (DOE) Argonne National Laboratory to use resources at the Center for Nanoscale Materials (CNM), a DOE Office of Science user facility at Argonne. After earning his degree, Polakovic joined Argonne as a postdoctoral researcher in 2020 and became a Maria Goeppert Mayer Fellow in October 2021 to develop superconducting nanowire particle detectors.
The Maria Goeppert Mayer Fellowship is an international award given to outstanding doctoral scientists and engineers to help them develop their careers in Argonne’s high-impact research environment. The fellowship honors Maria Goeppert Mayer, a theoretical physicist who earned the Nobel Prize in Physics in 1963 for her work at Argonne proposing a mathematical model for the structure of nuclear shells in the atomic nucleus. The fellowship provides early-career scientists the opportunity to pursue their own research directions, with the support of a sponsor and up to three years of funding. Here, Polakovic discusses his research on superconducting nanowires and how the fellowship contributed to his career development.
“My colleagues and I were the first ones to make nanowire particular detectors, and we still hold a few records. We broke the record for the strength of the magnetic field in which these detectors can operate by orders of magnitude.” — Tomas Polakovic, Argonne scholar
Q: What is your research focus at Argonne?
A: I’m working on superconducting nanowire particle detectors and electronics. These nanowires are very small, typically 10-20 nm thick and 100 nm wide. Because they’re made of superconducting materials, they have no electrical resistance at low temperatures, which means no energy is lost when electrons move through a device. At Argonne, I’m working on making superconducting nanowire particle detectors that can rapidly detect and track particles at small scales. These detectors have a variety of applications in nuclear physics, including their use in the Electron-Ion Collider and other types of particle accelerators. These superconducting nanowire sensors could also be used in cosmology to aid in the search for dark matter, for example.
Q: What are some of the major challenges with developing superconducting nanowires?
A: Making superconducting nanowires isn’t very different from the process used to make microchips, but it requires so much more infrastructure and funding. You need cryostats to keep your samples at extremely low temperatures and a ton of specialized equipment to set up and conduct experiments. Argonne’s Materials Science division and CNM have all the resources I need, so I’m well positioned to make progress on my research.
Q: What are your proudest achievements so far?
A: When I started working on this project, my colleagues and I were the first ones to make nanowire particle detectors, and we still hold a few records. We broke the record for the strength of the magnetic field in which these detectors can operate by orders of magnitude. And some preliminary results show we’ll be able to use these detectors to detect ultrarelativistic particles, which have velocities close to the speed of light.
Q: How did you discover Argonne and the Fellowship?
A: I earned my bachelor’s and master’s degrees in physics at Comenius University in Slovakia. My advisors and collaborators there knew about Argonne, so it’s a place that’s always been in the back of my mind. When I did my Ph.D. at Drexel University, I came to Argonne as a CNM user. The research I was doing required a lot of expensive equipment, which we didn’t have as a small research group. Using the CNM was the only option for advancing my research. While there, I heard about the Maria Goeppert Mayer Fellowship.
Q: What resources has the Fellowship provided to you?
A: The most important thing has been the three years of funding. I don’t have to worry about covering my salary or research expenses, which was critical for kickstarting my project. As a whole, Argonne is very well equipped for research in physics and nanoscale materials. You can do high-end research in a nice atmosphere with great people.
Q: How has the Fellowship contributed to your career development?
A: I’ve become a go-to person when it comes to research on superconducting devices, from particle detectors to electronics. The Fellowship has put me in a very good position to work on a variety of projects and develop new collaborations.
Q: What do you like doing outside of work?
A: I’m a semi-professional visual artist. These days, I mostly do generative art that I program, render and then put on canvas.
Q: What advice do you have for early-career scientists?
A: I would say pursue your research interests, but be very aware that a lot of luck was involved for me to be in the position I currently am.
About Argonne’s Center for Nanoscale Materials
The Center for Nanoscale Materials is one of the five DOE Nanoscale Science Research Centers, premier national user facilities for interdisciplinary research at the nanoscale supported by the DOE Office of Science. Together the NSRCs comprise a suite of complementary facilities that provide researchers with state-of-the-art capabilities to fabricate, process, characterize and model nanoscale materials, and constitute the largest infrastructure investment of the National Nanotechnology Initiative. The NSRCs are located at DOE’s Argonne, Brookhaven, Lawrence Berkeley, Oak Ridge, Sandia and Los Alamos National Laboratories. For more information about the DOE NSRCs, please visit https://science.osti.gov/User-Facilities/User-Facilities-at-a-Glance.
Argonne National Laboratory seeks solutions to pressing national problems in science and technology. The nation’s first national laboratory, Argonne conducts leading-edge basic and applied scientific research in virtually every scientific discipline. Argonne researchers work closely with researchers from hundreds of companies, universities, and federal, state and municipal agencies to help them solve their specific problems, advance America’s scientific leadership and prepare the nation for a better future. With employees from more than 60 nations, Argonne is managed by UChicago Argonne, LLC for the U.S. Department of Energy’s Office of Science.
The U.S. Department of Energy’s Office of Science is the single largest supporter of basic research in the physical sciences in the United States and is working to address some of the most pressing challenges of our time. For more information, visit https://energy.gov/science.