Local Manipulation and Measurement of Nonlocal Many-Body Operators in Lattice Gauge Theory Quantum Simulators

TL;DR

This paper proposes general schemes for measuring nonlocal observables like Wilson loops in lattice gauge theory quantum simulators using only local operations, aiding the study of gauge theories.

Contribution

It introduces novel methods for measuring nonlocal gauge-invariant operators in quantum simulators, facilitating nonperturbative studies of gauge theories.

Findings

Schemes enable measurement of Wilson loops and mesonic strings.

Applicable to various quantum simulation platforms.

Supports nonperturbative gauge theory research.

Abstract

Lattice Gauge Theories form a very successful framework for studying nonperturbative gauge field physics, in particular in Quantum Chromodynamics. Recently, their quantum simulation on atomic and solid-state platforms has been discussed, aiming at overcoming some of the difficulties still faced by the conventional approaches (such as the sign problem and real time evolution). While the actual implementations of a lattice gauge theory on a quantum simulator may differ in terms of the simulating system and its properties, they are all directed at studying similar physical phenomena, requiring the measurement of nonlocal observables, due to the local symmetry of gauge theories. In this work, general schemes for measuring such nonlocal observables (Wilson loops and mesonic string operators) in general lattice gauge theory quantum simulators that are based merely on local operations are proposed.