Native multiqubit Toffoli gates on ion trap quantum computers

TL;DR

This paper analyzes the implementation of multiqubit Toffoli gates on ion-trap quantum computers, assessing their performance, errors, and feasibility with current hardware constraints.

Contribution

It provides a detailed performance analysis of n-control-qubit Toffoli gates on ion-trap systems, including realistic error estimates and operational challenges.

Findings

Gates are feasible on current hardware but may be slow for quantum error correction.

Errors due to spin-phonon entanglement are quantitatively estimated.

Performance varies with ion shuttling and interaction zone parameters.

Abstract

We examine the detailed scenario for implementing n-control-qubit Toffoli gates and select gates on ion-trap quantum computers, especially those that shuttle ions into interaction zones. We determine expected performance of these gates with realistic parameters for an ion-trap quantum computer and taking into account the time variation of the exchange integrals. This allows us to estimate the errors due to spin-phonon entanglement as well. While there are challenges with implementing these gates, because their performance always has some degree of error, they should be feasible on current hardware, but they may be too slow to be used efficiently in quantum codes on noisy intermediate scale quantum computers.