Phonon mediated quantum spin simulator employing a planar ionic crystal in a Penning trap

TL;DR

This paper presents a method to create a quantum spin simulator using a planar ionic crystal in a Penning trap, by quantizing phonon modes and inducing spin-spin interactions with optical forces, enabling large-scale quantum simulations.

Contribution

It derives the normal modes for a rotating Coulomb ion crystal, quantizes them, and demonstrates how to generate and control spin-spin interactions for quantum simulation.

Findings

Normal modes for axial and planar vibrations are derived and quantized.

Spin-spin interactions can be engineered with different energy regimes.

Potential to simulate large quantum spin glasses.

Abstract

We derive the normal modes for a rotating Coulomb ion crystal in a Penning trap, quantize the motional degrees of freedom, and illustrate how they can by driven by a spin-dependent optical dipole force to create a quantum spin simulator on a triangular lattice with hundreds of spins. The analysis for the axial modes (oscillations perpendicular to the two-dimensional crystal plane) follow a standard normal-mode analysis, while the remaining planar modes are more complicated to analyze because they have velocity-dependent forces in the rotating frame. After quantizing the normal modes into phonons, we illustrate some of the different spin-spin interactions that can be generated by entangling the motional degrees of freedom with the spin degrees of freedom via a spin-dependent optical dipole force. In addition to the well-known power-law dependence of the spin-spin interactions when driving the axial modes blue of phonon band, we notice certain parameter regimes in which the level of frustration between the spins can be engineered by driving the axial or planar phonon modes at different energies. These systems may allow for the analog simulation of quantum spin glasses with large numbers of spins.