Klaus Bartschat, retired Ellis and Nelle Levitt distinguished professor of physics, was awarded a three-year, $319,000 National Science Foundation grant for his project on photon and electron-driven atomic collision processes.
In 2023, Bartschat’s contributions to the field were recognized via citation by the Nobel Prize in Physics, awarded for the development of extremely short laser pulses — technology that enables the imaging of electron dynamics in atoms and molecules.
Although Bartschat has retired from teaching with the department of physics and astronomy at Drake, he is still actively engaged in research at the University. Originally from Germany, Bartschat started his career as an experimental physicist only to discover that it “wasn’t his cup of tea.” During his master’s thesis, he preferred working out the theory of his experiment over spending all his time in the lab.
“I didn’t break anything, and I did good on my theoretical part [of the experiment],” Bartschat said.
Impressed by his ability, Bartschat’s professor urged him to join a PhD program.
“He said, ‘You design an experiment, you say what you would like to measure and then you also develop the theory for that experiment.’ And I said, ‘Thank you very much for your confidence, but let me just do the theory and you find somebody who just does work in the lab.’” Bartschat said.
Bartschat did exactly that. He became a full-time theorist and got a PhD in theoretical physics in Belfast as well as a special German degree based on self-directed research to fulfill the minimum requirements to be a professor in the German system.
“I got a job that basically didn’t require me to be there, so I could just travel around the world, and that’s what I did,” Bartschat said.
Traveling around the world eventually led Bartschat to Drake, where he started his projects on electron collisions. His research focuses on the interaction of light, mostly in the form of lasers and charged particles — primarily electrons — with atoms and ions. The results of this interaction are not only vital to understanding fundamental collision dynamics but also provide accurate open-source atomic data that can be used for a variety of applications — from modeling planetary atmospheres to cancer research.
Bartschat’s transition to full-time theorist allowed him to focus on developing theories that are “crucial” to guiding experimentalists through challenges.
Bartschat also works with intense, short light pulses, exploring atomic and molecular reactions that occur at incredibly brief time scales — measured in attoseconds. This research aims to manipulate electrons at the atomic level, with the potential to revolutionize fields ranging from drug development to material science.
Unfortunately for scientists, controlling electrons is easier said than done. Creating a laser system with two electrons requires exact precision from both the system and controller.
“One second has about twice as many attoseconds as the believed established age of the universe has seconds,” Bartschat said. “So, this is short, very, very short — one billionth of one billionth of a second. If you have a very intense pulse, you really can rattle the atom in ways that haven’t been rattled before.”
This work is important to facilitate further developments in the imaging and control of sub-microscopic reactions, which could impact fields from drug development to the material sciences. One of Bartschat’s initiatives includes collaboration with Oak Ridge National Lab to enrich terbium for cancer treatment.
Collaboration is at the heart of Bartschat’s work — all his data is open source. He has established strong partnerships with international teams, including projects with the Max Planck Institute in Heidelberg, Germany; North America; Europe and Australia as well as collaborative efforts with researchers in China. These collaborations not only strengthen his research but, since his research is to “help, hopefully, the world,” strengthens the research of others.
A key player in this collaborative environment is Juan Carlos del Valle, a postdoctoral researcher at Drake. Working closely with Bartschat, he is focused on reviving and enhancing an invaluable piece of code left behind by a former researcher and Drake professor Oleg Zatsarinny.
“This code is exceptional,” Del Valle explained. “It allows us to perform detailed atomic calculations, such as collision calculations and scattering amplitudes.”
Del Valle is currently constructing an interface between this code and another tool called RMT, aimed at tackling attosecond problems — an area that has gained significant attention, especially after recent Nobel Prize recognition.
Del Valle describes his experience working with Bartschat as transformative.
“[Bartschat] is a magnificent researcher, and I’ve learned so much in just a year,” Del Valle said. “He’s like a library; there’s so much knowledge in him.”
For Del Valle, working with Bartschat has not only provided him with technical expertise but also afforded him the credentials needed for a future in research — a dream he long aspired to achieve amidst fierce global competition for academic roles.
With ongoing funding, the satisfaction of working with dedicated colleagues, a passion for exploration and the hope to make a positive impact on the world, Bartschat continues to make contributions to the field of physics, striving to bridge the gap between theoretical and experimental physicists.
“When I talk about my stuff, my eyes light up,” Bartschat said. “I love this stuff and that’s why I retired from teaching, but I negotiated that I could stay here.”
