Radial two-dimensional ion crystals in a linear Paul trap

TL;DR

This paper experimentally investigates 2D Coulomb ion crystals in a linear Paul trap, demonstrating their structural stability, vibrational properties, and potential for quantum simulation applications.

Contribution

It provides the first detailed experimental characterization of radial-2D ion crystals, confirming theoretical models and showing their suitability for quantum simulation.

Findings

Structural phase boundaries match pseudopotential predictions

Micromotion-induced heating is confined to the radial plane

Transverse motional modes remain decoupled and cold

Abstract

We experimentally study two-dimensional (2D) Coulomb crystals in the "radial-2D" phase of a linear Paul trap. This phase is identified by a 2D ion lattice aligned entirely with the radial plane and is created by imposing a large ratio of axial to radial trapping potentials. Using arrays of up to 19 $^{171}$Yb$^+$ ions, we demonstrate that the structural phase boundaries and vibrational mode frequencies of such crystals are well-described by the pseudopotential approximation, despite the time-dependent ion positions driven by intrinsic micromotion. We further observe that micromotion-induced heating of the radial-2D crystal is confined to the radial plane. Finally, we verify that the transverse motional modes, which are used in most ion-trap quantum simulation schemes, remain decoupled and cold in this geometry. Our results establish radial-2D ion crystals as a robust experimental platform for realizing a variety of theoretical proposals in quantum simulation and computation.