The quantum computing company Quantinuum and a DESY team led by Karl Jansen, head of the Center of Quantum Technology and Applications (CQTA) at DESY, have achieved an important milestone. Using Quantinuum’s H1 quantum computer they studied a model in Lattice Gauge Theory, a mathematical tool used to understand fundamental processes in nature.

For the first time, they were able to compute the full wavefunction of a two-dimensional confinement system, Quantum Electrodynamics (QED), on a quantum processor. Confinement describes systems in which certain particles cannot occur unbound. In particular, the researchers were able to visualize the confining string, which connects the particles in QED and even the string-breaking phenomenon, which cannot be easily studied with classical computers. The team, comprising of Arianna Crippa and Karl Jansen from DESY and EnricoRinaldi form Quantinuum, approached the problem using Quantinuum software packages which allowed to reduce the size of their quantum circuit from 24 qubits to 15, making the simulations significantly more efficient. Just like in electrical circuits, for example, the smaller a quantum circuit is, the faster and more accurately it works.

One key element of the project was the usage of Quantinuum’s H1 quantum computer, a system based on trapped ions, which allows arbitrary connectivity and is built with long-coherence qubits and high-fidelity gates, quantum gates that work with particularly high precision.

This research is an important step towards simulating more complex systems in the future, such as Quantum Chromodynamics (QCD) – the theory that describes the strong forces holding atomic nuclei together. Achieving this could help answer fundamental questions about the universe, such as how it began, the structure of neutron stars, and why matter behaves the way it does.

“Our collaboration with Quantinuum has given us the possibility to gain new insights into physical phenomena in an important quantum field theory,” says Jansen. Rinaldi adds, "I am excited to see quantum computing being adopted by the HEP community. Research in our field is often incredibly computationally demanding and quantum computing will help meet those needs. Our recent results prove this point: we were able to study the full wavefunction of a 2D confining system using only 15 qubits. Imagine what we can do with 100." And, Crippa expresses her excitement. "As a PhD student, collaborating with Quantinuum on this project was a very enriching experience. Working alongside experts of quantum computing technology allowed me to see the potential of quantum computing in action."

This work is part of a larger global effort to use quantum computers for high-energy physics. Scientists around the world are exploring similar problems with different types of quantum technologies. These expected results can lead to new breakthroughs, which would demonstrate that quantum computers could revolutionize our understanding of the universe.