Entanglement Generation Using Discrete Solitons in Coulomb Crystals

TL;DR

This paper proposes a method to generate entanglement in Coulomb crystal ion traps using discrete solitons, leveraging their localized modes and topological protection, suitable for large 2D and 3D systems.

Contribution

It introduces a novel approach to entanglement generation utilizing the unique properties of discrete solitons in ion crystals, accounting for micromotion effects in RF traps.

Findings

Discrete solitons support localized motional modes suitable for entanglement.

The method is effective with Doppler and sideband cooling techniques.

Gap separation of soliton modes is nearly independent of crystal size.

Abstract

Laser cooled and trapped ions can crystallize and feature discrete solitons, that are nonlinear, topologically-protected configurations of the Coulomb crystal. Such solitons, as their continuum counterparts, can move within the crystal, while their discreteness leads to the existence of a gap-separated, spatially-localized motional mode of oscillation above the spectrum. Suggesting that these unique properties of discrete solitons can be used for generating entanglement between different sites of the crystal, we study a detailed proposal in the context of state-of-the-art experimental techniques. We analyze the interaction of periodically-driven planar ion crystals with optical forces, revealing the effects of micromotion in radio-frequency traps inherent to such structures, as opposed to linear ion chains. The proposed method requires Doppler cooling of the crystal and sideband cooling of the soliton's localized modes alone. Since the gap separation of the latter is nearly independent of the crystal size, this approach could be particularly useful for producing entanglement and studying system-environment interactions in large, two- and possibly three-dimensional systems.