A research team led by faculty at the Duke Quantum Center (DQC) has observed string-breaking dynamics related to particle-antiparticle formation on a quantum simulator, one of the first in the quantum-physics field.
This approach, described in the journal Nature Physics on September 23, shows the viability of trapped-ion quantum computers to begin probing fundamental questions about the universe. The experiment emulates a phenomenon called string-breaking in which two connected fundamental building blocks of matter stretch apart, eventually creating so much energy that new particles "pop into existence" when the connection snaps.
"Quantum computer simulations provide the best platform to investigate complex questions like matter formation, short of having witnessed the Big Bang itself," said Christopher Monroe , the Gilhuly Family Presidential Distinguished Professor of Electrical and Computer Engineering and Physics at Duke, who led this research. "These findings signal a marked development in the quantum science field and open new avenues for us to understand string-breaking dynamics."
This research was conducted by an international collaboration including the University of Maryland (UMD), Oxford University, California Institute of Technology, Cornell University and KU Leuven. The results join two similar published findings, led by other research teams in the field, which simulated the same phenomenon on different quantum computer platforms.
Building Blocks of Matter
The fundamental building blocks of matter, quarks, only exist when bound together inside particles such as protons and neutrons. They are about a billion times smaller than an atom and can't currently be observed directly. You can imagine pairs of quarks like two tiny, charged particles connected by a taut string; they want to stick together, so it takes quite a bit of energy to pull them apart.
But once they are forced apart, the energy built up in their connection can be enough to create more charged particles, since mass and energy are directly related through Einstein's famous equation E=mc2. When this happens, the string snaps, leaving two or more pairs of particles rather than one. This process requires so much energy, however, that it only happens in extreme environments like the Large Hadron Collider or the aftermath of the Big Bang.
In the new study, the team led by DQC successfully observed analogous string-breaking dynamics on a trapped-ion quantum platform. Quantum simulators, with their high degree of controllability, can be programmed to recreate the real-world processes occurring at the atomic or even subatomic quantum scales.
"Working at the intersection of quantum simulation and high-energy physics is incredibly exciting," said Arinjoy De, first author on the paper, former PhD student in Monroe's lab and now production machine lead at QuEra Computing. "By simulating quark confinement and string-breaking phenomena in a controlled lab environment, we're opening up new pathways for experimental investigations into the behavior of matter at its most fundamental level."
How the Simulation Worked
To perform the simulation, the team encoded a string-breaking model into a chain of 13 trapped ions. Using precisely controlled laser beams, researchers were able to tune the interactions among the ions. These interactions effectively control the energy to the system in a way that mimics the stretching and eventual breaking of a string.
By preparing the system in an out-of-equilibrium state and tracking its evolution over time, the researchers observed the emergence of effective charges and reconstructed the resulting string dynamics.
The team also simulated the process on a classical computer and confirmed that the experimental quantum-computed results were accurate. As the problem size grows in future experiments, however, only quantum computers, not classical computers, will be able to solve these problems.
The string-breaking process in other models was also recreated by the teams led by Google and QuEra Computing on platforms built by superconducting circuits and neutral atoms, respectively, which each have their own advantages and challenges.
"These are the three platforms leading the charge in quantum computing, so it's a nice benchmark and comparison for the quantum community," added Monroe.
The trapped-ion platform results mark an exciting step forward in building quantum simulations complex enough to exceed the capabilities of even the largest supercomputers, which will eventually allow researchers to explore the most fundamental questions of the universe, like matter evolution after the Big Bang.
"As a physicist, it is incredibly exciting to investigate the conditions of the early universe in an atomic-level computing machine," said Zohreh Davoudi, associate professor of physics at UMD, who was part of the research team. "Even the slightest insights from an out-of-equilibrium physics model will guide us in the future."
This work was supported by the Department of Energy (DE-SC0020312, DE-SC0025341, DESC0019040, DE-SC0024220, DE-SC0020271), National Science Foundation (OMA-2120757), Air Force Office of Scientific Research, Defense Advanced Research Projects Agency and Amazon Web Services.
"Observation of string-breaking dynamics in a quantum simulator." Arinjoy De, Alessio Lerose, De Luo, Federica M. Surace, Alexander Schuckert, Elizabeth R. Bennewitz, Brayden Ware, William Morong, Kate S. Collins, Zohreh Davoudi, Alexey V. Gorshkov, Or Katz, and Christopher Monroe. Nature Physics, 2026. DOI: 10.1038/s41567-026-03422-0
