Jason Youm, a high school student who performed summer research with Alexey Gorshkov, an adjunct associate professor of physics at UMD, in 2023, placed in the top dozen competitors in the physics and astronomy category at the Regeneron International Science and Engineering Fair (ISEF). In the competition, Youm, who recently completed his junior year at Montgomery Blair High School in Silver Spring, Maryland, presented research he completed under the mentorship of Gorshkov and Joseph Iosue, a graduate student in physics at UMD.

The Regeneron ISEF brings together high school students from across the world who earn their spots by qualifying at local science fairs. In his project, Youm performed calculations to help researchers investigate how quantum computers can perform certain tasks significantly faster than their traditional counterparts.

“I'm truly, really thankful for the research opportunity,” Youm said. “I think it's honestly changed my life. It's truly an invaluable experience.”

Youm had harbored an interest in quantum physics for the first couple of years of high school, and after finishing his first calculus class during his sophomore year, he decided to look for opportunities to explore the interest more deeply.

“Kind of on a whim, in mid-May, I just emailed some professors at UMD, because I heard they had a good program in quantum physics,” Youm said. “I just asked like, ‘I'm interested in these fields. Would you be interested in having a student intern during the summer?’ And Alexey was kind enough to accept me into the group.”

Gorshkov first looked over the relevant experience in math and physics Youm shared in his email and then reached out to the other members of the group to ask if any of them had a suitable project.

One of those graduate students, Iosue, was particularly interested in mentoring someone since he knew firsthand how valuable such experiences can be. When he was an undergraduate at the Massachusetts Institute of Technology (MIT), he had spent a summer working in Gorshkov’s group.

“My time as an undergrad in Alexey’s group was a very good experience for me,” Iosue said. “It was the best research experience I had until I started my Ph.D. So, I wanted to do something similar for someone else.”

Iosue remembered a project from his early days as a graduate student that had a natural continuation. The group hadn’t followed up on the possibility yet, and he thought the remaining work might be a suitable project for a motivated high school student.

The project developed mathematical tools for studying quantum entanglement—a phenomenon where the evolving fates of quantum particles become inextricably linked. A collection of quantum states can have different amounts of quantum entanglement that are possible, and Iosue performed calculations that help quantify if the quantum entanglement values are tightly or loosely clumped together. Entanglement plays a central role in quantum computers, so it is likely to be a key ingredient in any proof that quantum computing’s advantage is real and that a cleverly designed program on a traditional computer can’t possibly compete.

The calculations that Iosue had performed were only the first of a set that each provide slightly different insights about the entanglement of the analyzed states. Iosue suggested that Youm could perform the other calculations by using the previous work as a guide. Gorshkov agreed, and Youm ended up taking on the project.

“My hope was that the calculations would be similar—like the whole beginning to end process that we did would be similar,” Iosue said. “So, it seemed like a high school student wouldn't have to necessarily dive into too much scientific literature or dive into too much uncertainty. I was hoping there was a bit more of a straight path, but with research, it's not always what you expect.”

Early in the summer, the project hit a snag. Iosue suggested Youm begin with a scientific paper that provided equations that were the natural starting point for the new calculations. But as Youm worked, his results weren’t going anywhere. When the group dug deeper, they determined that the equations in the paper were incorrect, and they had to start over by deriving the initial equations themselves.

Eventually, Youm successfully worked through the math for an additional portion of the calculations, and he also used computer simulations to verify his results.

“In the middle of the project was a lot of coding, mathematical work, and trying to understand the physics processes behind all the math that I was doing,” Youm said. “I worked for around eight hours a day, just trying to progress in my work and deriving the necessary formulas and the theorems. So it was pretty intensive, but also I really enjoyed it.”

In Youm’s science fair project, titled “Measuring Quantum Entanglement Entropy in Gaussian Boson Sampling,” he presented the results and discussed their practical applications to quantum experiments. The calculations apply to Gaussian boson sampling experiments where several measurements collect a sample of results from a specific set of prepared quantum states. Quantum mechanics allows a sample to be designed so that it reflects very specific statistics, and many physicists believe that for many cases it can be prohibitively complex for any computer not exploiting quantum phenomena to create a sample with the correct statistics.

The calculations that Youm performed are not directly used in sampling experiments, but they are a potential tool for studying how entanglement relates to the complexity of the sampling task. Understanding entanglement could be central to definitively proving if a sampling experiment has truly achieved an unassailable quantum advantage.

After the summer, Youm continued to work with the group—scheduling meetings around his normal school schedule and assignments. During the school year, Youm took the lead on writing a paper about the results, which the group has posted on the arXiv preprint server.

“I've had high school students working with my group in the past, but this was the first time we worked over the summer with a rising junior instead of a rising senior,” said Gorshkov. “Jason's performance was outstanding!”

This summer Youm is once again took on a research project, but this year he was at the 2024 Center for Excellence in Education Research Science Institute summer program at MIT, which accepts 100 high school students from around the world.

“I am really thankful for Alexey, and the rest of the research group, because without them I wouldn't have been able to get any of these opportunities,” Youm said. “I owe all of this to them, and I just feel really happy and grateful.”

*Written by Bailey Bedford*

In addition to Gorshkov and Iosue, QuICS Hartree Postdoctoral Fellow Yuxin Wang and JQI graduate student Adam Ehrenberg also worked with Youm and are authors on the paper posted on the arXiv preprint server.