Observation of Domain Wall Confinement and Dynamics in a Quantum Simulator

TL;DR

This paper reports the first experimental observation of magnetic domain wall confinement in a quantum simulator, revealing how confinement suppresses information spread and enables studying high-energy physics phenomena in quantum many-body systems.

Contribution

It demonstrates magnetic domain wall confinement in a trapped-ion quantum simulator and shows how it affects dynamics and excitations, opening avenues for simulating high-energy physics.

Findings

Confinement suppresses information propagation in spin chains.

Quantitative measurement of domain wall bound state energies.

Ability to explore complex regimes difficult for classical computation.

Abstract

Confinement is a ubiquitous mechanism in nature, whereby particles feel an attractive force that increases without bound as they separate. A prominent example is color confinement in particle physics, in which baryons and mesons are produced by quark confinement. Analogously, confinement can also occur in low-energy quantum many-body systems when elementary excitations are confined into bound quasiparticles. Here, we report the first observation of magnetic domain wall confinement in interacting spin chains with a trapped-ion quantum simulator. By measuring how correlations spread, we show that confinement can dramatically suppress information propagation and thermalization in such many-body systems. We are able to quantitatively determine the excitation energy of domain wall bound states from non-equilibrium quench dynamics. Furthermore, we study the number of domain wall excitations created for different quench parameters, in a regime that is difficult to model with classical computers. This work demonstrates the capability of quantum simulators for investigating exotic high-energy physics phenomena, such as quark collision and string breaking.