Quantum Computers Simulate String Breaking in Subatomic Particle Interactions

Subatomic particles such as quarks can be linked by "strings" of force fields that release energy when stretched to the point of breaking. Recently, two international research teams successfully simulated this phenomenon using quantum computers and observed the dynamic process in real time. Published in Nature, the work marks a significant advance in leveraging quantum computing for complex simulations beyond the reach of classical computers.

According to physicists at the U.S. Lawrence Berkeley National Laboratory, string breaking is a key process in particle physics that remains poorly understood. While classical computers can calculate the end results of particle collisions, they struggle to simulate the full intermediate dynamics. This quantum approach offers a new pathway to explore such processes.

In their experiments, one team used the Aquila quantum processor developed by U.S. startup QuEra, encoding information in atoms arranged in a two-dimensional honeycomb lattice and held in place with optical tweezers to simulate electric fields. The other team employed Google's Sycamore chip, using superconducting loops to encode quantum fields. These approaches represent two distinct strategies: analog quantum simulation, where atomic interactions evolve naturally under electromagnetic forces, and digital quantum simulation, where systems are manipulated through discrete quantum operations.

The simulations revealed that the force-field strings in the system could exhibit rigidity, vibration, or break apart—sometimes even resulting in particle unbinding. Although the findings may have implications for condensed matter research, they still fall short of replicating the full three-dimensional high-energy interactions observed in particle colliders, such as those governed by the strong nuclear force. Experts acknowledge that a complete simulation of high-energy physics remains an unsolved challenge.