In-Situ Rewiring of Two-Dimensional Ion Lattice Interactions Using Metastable State Shelving

TL;DR

This paper demonstrates in-situ reconfiguration of ion lattice geometries in trapped-ion systems by shelving ions in metastable states, effectively controlling qubit interactions without physical rearrangement.

Contribution

It introduces a method to dynamically reconfigure ion lattice interactions using metastable state shelving, enabling flexible quantum simulations.

Findings

Metastable state shelving removes ions from quantum dynamics.

Deshelving rate is much slower than interaction rate.

Deshelving rate scales quadratically with laser intensity.

Abstract

Trapped-ion lattice geometries, which determine the interactions between trapped-ion qubits, are typically governed by the balance of Coulomb repulsion forces with the external trapping potential. Here we demonstrate how the effective ion lattice geometry and resulting qubit-qubit interactions may be reconfigured in-situ, by shelving specific ions in metastable states outside the qubit subspace. Using a triangular lattice of three $^{171}$Yb$^{+}$ ions, we optically pump selected ions into the long-lived $^2F_{7/2}$ state. We then apply a global Ising-like Hamiltonian to the system and verify that the shelved qubits are fully removed from participation in the quantum dynamics. We characterize the metastable state lifetime in the presence of laser-driven ion-ion interactions, finding a deshelving rate that is orders of magnitude slower than the spin-spin interaction rate and scales quadratically with applied laser intensity.