Quantum computation of hadron scattering in a lattice gauge theory

TL;DR

This paper demonstrates the digital quantum simulation of two-hadron scattering in a 1+1 dimensional $Z_2$ lattice gauge theory using trapped-ion quantum computers, highlighting the potential of quantum computing in high-energy physics.

Contribution

It introduces an efficient algorithm for preparing multi-hadron states and simulating their collisions on quantum hardware, advancing quantum simulation of gauge theories.

Findings

High-fidelity initial state preparation achieved

Simulation results consistent with classical numerics at early times

Decoherence limits long-time evolution accuracy

Abstract

We present a digital quantum computation of two-hadron scattering in a $Z_2$ lattice gauge theory in 1+1 dimensions. We prepare well-separated single-particle wave packets with desired momentum-space wavefunctions, and simulate their collision through digitized time evolution. Multiple hadronic wave packets can be produced using the efficient, systematically improvable algorithm of this work, achieving high fidelity with the target initial state. Specifically, employing a trapped-ion quantum computer (IonQ Forte), we prepare up to three meson wave packets using 11 and 27 system qubits, and simulate collision dynamics of two meson wave packets for the smaller system. Results for local observables are consistent with numerical simulations at early times, but decoherence effects limit evolution into long times. We demonstrate the critical role of high-fidelity initial states for precision measurements of state-sensitive observables, such as $S$-matrix elements. Our work establishes the potential of quantum computers in simulating hadron-scattering processes in strongly interacting gauge theories.