Digital quantum simulations of scattering in quantum field theories using W states

TL;DR

This paper demonstrates quantum simulation of particle scattering in quantum field theories on IBM quantum computers, revealing inelastic particle production and introducing a novel, efficient wavepacket preparation algorithm applicable to various models.

Contribution

It introduces a new quantum algorithm for preparing wavepackets with minimal circuit depth, enabling advanced scattering simulations on quantum computers.

Findings

Evidence of inelastic particle production in 1D Ising field theory

Successful simulation of post-collision dynamics on 104 qubits

Efficient wavepacket preparation method with circuit depth independent of wavepacket size

Abstract

High-energy particle collisions can convert energy into matter through the inelastic production of new particles. Quantum computers are an ideal platform for simulating the out-of-equilibrium dynamics of collisions and the formation of subsequent many-particle states. In this work, evidence for inelastic particle production is observed in one-dimensional Ising field theory using IBM's quantum computers. The scattering experiment is performed on 104 qubits of ibm_marrakesh and uses up to 5,589 two-qubit gates to access the post-collision dynamics. An outgoing heavy particle produced in the collision is identified from the skewness of the measured energy density. Integral to this computation is a new quantum algorithm for preparing the initial state (wavepackets) of a quantum field theory scattering simulation. This method efficiently prepares wavepackets by extending recent protocols for creating W states with mid-circuit measurement and feedforward. The required circuit depth is independent of wavepacket size and spatial dimension, representing a superexponential improvement over previous methods. Our wavepacket preparation algorithm can be applied to a wide range of lattice models and is demonstrated in one-dimensional Ising field theory, scalar field theory, the Schwinger model and two-dimensional Ising field theory.