Quantum Simulations for Strong-Field QED

TL;DR

This paper demonstrates quantum simulations of strong-field QED processes, specifically Breit-Wheeler pair production, in 3+1 dimensions, showing promising agreement with classical results and exploring error mitigation techniques for near-term quantum hardware.

Contribution

It develops a quantum circuit approach for simulating strong-field QED in 3+1 dimensions and introduces error mitigation strategies tailored for Trotterized quantum simulations.

Findings

Quantum simulations align well with classical results after error mitigation.

An asymmetric depolarization algorithm improves simulation accuracy.

Feasible approach for near-term quantum hardware to study SFQED processes.

Abstract

Quantum field theory in the presence of strong background fields contains interesting problems where quantum computers may someday provide a valuable computational resource. In the NISQ era it is useful to consider simpler benchmark problems in order to develop feasible approaches, identify critical limitations of current hardware, and build new simulation tools. Here we perform quantum simulations of strong-field QED (SFQED) in $3+1$ dimensions, using real-time nonlinear Breit-Wheeler pair-production as a prototypical process. The strong-field QED Hamiltonian is derived and truncated in the Furry-Volkov mode expansion, and the interactions relevant for Breit-Wheeler are transformed into a quantum circuit. Quantum simulations of a "null double slit" experiment are found to agree well with classical simulations following the application of various error mitigation strategies, including an asymmetric depolarization algorithm which we develop and adapt to the case of Trotterization with a time-dependent Hamiltonian. We also discuss longer-term goals for the quantum simulation of SFQED.