Bringing the promise of quantum computing to nuclear physics

Quantum mechanics, the physics of atoms and subatomic particles, can be strange, especially compared to the everyday physics of Isaac Newton’s falling apples. But this unusual science is enabling researchers to develop new ideas and tools, including quantum computers, that can help demystify the quantum realm and solve complex everyday problems.

An artist’s rendering of a quantum computer simulating an atom’s nucleus, Image credit: Facility for Rare Isotope Beams

That’s the goal behind a new U.S. Department of Energy (Office of Science (DOE-SC) grant, awarded to Michigan State University (MSU) researchers, led by physicists at Facility for Rare Isotope Beams (FRIB). Working with Los Alamos National Laboratory, the team is developing algorithms – essentially programming instructions – for quantum computers to help these machines address problems that are difficult for conventional computers. For example, problems like explaining the fundamental quantum science that keeps an atomic nucleus from falling apart.

The award, provided by the Office of Nuclear Physics within DOE-SC, is the latest in a growing list of grants supporting MSU researchers developing new quantum theories and technology.

“The aim is to improve the efficiency and scalability of quantum simulation algorithms, thereby providing new insights on their applicability for future studies of nuclei and nuclear matter,” said principal investigator Morten Hjorth-Jensen, an FRIB researcher who is also a professor in MSU’s Department of Physics and Astronomy and a professor of physics at the University of Oslo in Norway.

Although this grant focuses on nuclear physics, the algorithms it yields could benefit other fields looking to use quantum computing’s promise to more rapidly solve complicated problems. This includes scientific disciplines such as chemistry and materials science, but also areas such as banking, logistics, and data analytics.

“There is a lot of potential for transferring what we are developing into other fields,” Hjorth-Jensen said. “Hopefully, our results will lead to an increased interest in theoretical and experimental developments of quantum information technologies.” All the algorithms developed as part of this work will be publicly available, he added.

What makes quantum computers attractive tools for these applications is a freedom afforded by quantum mechanics.

Classical computers are constrained to a binary system of zeros and ones with transistors that are either off or on. The restrictions on quantum computers are looser.

Instead of transistors, quantum computers use technology called qubits (pronounced “q-bits”) that can be both on and off at the same time. Not somewhere in between, but in both opposite states at once.

Combined with the proper algorithms, this freedom enables quantum computers to run certain calculations much faster than their classical counterparts. The type of calculations, for instance, capable of helping scientists explain precisely how swarms of elementary particles known as quarks and gluons hold atomic nuclei together.

"It is really hard to do those problems,” said Huey-Wen Lin, a co-investigator on the grant. “I don’t see a way to solve them any time soon with classical computers.”

Lin is an assistant professor in the Department of Physics and Astronomy and the Department of Computational Mathematics, Science and Engineering at MSU.

She added that quantum computers won’t solve these problems immediately, either. But the timescales could be measured in years rather than careers.

Hjorth-Jensen believes this project will also help accelerate MSU’s collaborations in quantum computing. Formally, this grant supports a collaboration of eight MSU researchers and staff scientist Patrick Coles at Los Alamos National Laboratory.

But Hjorth-Jensen hopes the project will spark more discussions and forge deeper connections with the growing community of quantum experts across campus and prepare the next generation of researchers. The grant will also open up new opportunities in quantum computing training for MSU students who are studying in the nation’s top-ranked nuclear physics graduate program.

The grant, titled “From Quarks to Stars: A Quantum Computing Approach to the Nuclear Many-Body Problem,” was awarded as part of “Quantum Horizons: Quantum Information Systems Research and Innovation for Nuclear Science," a funding opportunity issued by DOE-SC.

Hjorth-Jensen and Lin are joined on this grant by their MSU colleagues Alexei Bazavov and Matthew Hirn from the Department of Computational Mathematics, Science and Engineering; Scott Bogner, Heiko Hergert, Dean Lee and Andrea Shindler from FRIB, and the Department of Physics and Astronomy. Hirn is also an assistant professor in the Department of Mathematics.