Researchers Use IBM Quantum Hardware to Model a Key Particle Physics Process

A research scientist at Lawrence Berkeley National Laboratory has successfully simulated hadronization, a fundamental particle physics process, using IBM quantum hardware. By leveraging the Quantum Computer User Program at Oak Ridge National Laboratory, the study demonstrates how quantum bits can represent subatomic interactions that are computationally prohibitive for classical supercomputers. This milestone provides a foundational framework for using quantum systems to explore the structure of matter and search for new physics at colliders like the Large Hadron Collider.

Anthony Ciavarella, a research scientist at Lawrence Berkeley National Laboratory, led the project using an IBM Quantum Platform Heron processor to model the process of hadronization. Accessed via the Quantum Computer User Program (QCUP) at the Oak Ridge Leadership Computing Facility, the simulation utilized 104 of the processor’s 156 qubits. Hadronization occurs when quarks bind via the strong nuclear force to form composite particles like protons and neutrons, a process that physical experiments at the Large Hadron Collider (LHC) can only measure indirectly. By using quantum hardware, researchers aim to fill the gaps in scientific observations that classical simulations cannot currently address due to the complexity of the calculations.

The core challenge in modeling these systems on classical computers lies in quantum chromodynamics (QCD), the theory describing how the strong force binds quarks and gluons. Classical binary systems face an exponential scaling problem where the memory required to represent quantum states doubles with every additional particle or time step. In contrast, quantum computers are more efficient because qubits can exist in superposition and naturally represent the entanglement and quantum correlations inherent in subatomic systems. Ciavarella highlighted that the ability of quantum computers to handle this phenomenology was a primary motivation for their development, offering a path to predictions that are too difficult for even exascale-class classical supercomputers like Frontier.

To conduct the simulation on current-generation hardware, which is still prone to errors, Ciavarella utilized a simplified model incorporating a heavy quark limit to simulate string breaking. This mechanism involves gluon strings stretching and snapping to create new quark-antiquark pairs. Heavy quarks were chosen for this initial step because their mass allows them to be more easily represented as points on a simulation grid compared to light quarks. The findings, published in Physical Review D, represent a significant step toward developing the computational techniques required to simulate large subatomic systems on the more powerful, lower-error quantum computers expected in the near future.