Classically emulated digital quantum simulation for screening and confinement in the Schwinger model with a topological term

TL;DR

This paper uses classical simulation of digital quantum methods to study confinement and screening in the Schwinger model with a topological term, confirming theoretical predictions about charge behavior.

Contribution

It demonstrates the application of digital quantum simulation to gauge theories with topological terms, providing insights into confinement phenomena in a (1+1)-dimensional setting.

Findings

Good agreement between simulation and analytical results.

Linear potential for non-integer charges, non-linear for integer charges.

Confirmation of confinement and screening behaviors.

Abstract

We perform digital quantum simulation, using a classical simulator, to study screening and confinement in a gauge theory with a topological term, focusing on ($1+1$)-dimensional quantum electrodynamics (Schwinger model) with a theta term. We compute the ground state energy in the presence of probe charges to estimate the potential between them, via adiabatic state preparation. We compare our simulation results and analytical predictions for a finite volume, finding good agreements. In particular our result in the massive case shows a linear behavior for non-integer charges and a non-linear behavior for integer charges, consistently with the expected confinement (screening) behavior for non-integer (integer) charges.