Quantum simulation of a lattice Schwinger model in a chain of trapped ions

TL;DR

This paper proposes a method to simulate the lattice Schwinger model, a key example of lattice gauge theories, using trapped ions, enabling the study of fundamental quantum electrodynamics phenomena in controllable quantum systems.

Contribution

It introduces a scheme to realize gauge-invariant dynamics in trapped-ion systems for simulating one-dimensional quantum electrodynamics models.

Findings

Observation of spontaneous parity- and charge-symmetry breaking

Demonstration of false-vacuum decay in a minimal ion setup

Feasibility of simulating gauge theories with realistic experimental imperfections

Abstract

We discuss how a lattice Schwinger model can be realized in a linear ion trap, allowing a detailed study of the physics of Abelian lattice gauge theories related to one-dimensional quantum electrodynamics. Relying on the rich quantum-simulation toolbox available in state-of-the-art trapped-ion experiments, we show how one can engineer an effectively gauge-invariant dynamics by imposing energetic constraints, provided by strong Ising-like interactions. Applying exact diagonalization to ground-state and time-dependent properties, we study the underlying microscopic model, and discuss undesired interaction terms and other imperfections. As our analysis shows, the proposed scheme allows for the observation in realistic setups of spontaneous parity- and charge-symmetry breaking, as well as false-vacuum decay. Besides an implementation aimed at larger ion chains, we also discuss a minimal setting, consisting of only four ions in a simpler experimental setup, which enables to probe basic physical phenomena related to the full many-body problem. The proposal opens a new route for analog quantum simulation of high-energy and condensed-matter models where gauge symmetries play a prominent role.