A research team has developed a toolset to evaluate the performance of gate sets built from native Mølmer–Sørensen multiqubit gates in trapped-ion quantum computers. The goal is to determine precisely when the added engineering complexity of these gates translates into a real improvement in running quantum algorithms, and when the effort is not worthwhile.

Trapped-ion quantum computers are considered a promising platform for reaching quantum advantage, thanks to their long coherence times, near all-to-all connectivity, and the possibility of implementing gates that act on several qubits at once. These features are the technology's main selling point compared with competing platforms, but until now there was no systematic way to quantify in which specific scenarios a more flexible multiqubit gate improves an algorithm's performance.

The work addresses this question by using unitary synthesis as an application-agnostic benchmark target. On that basis, the team identifies specific hardware requirements that multiqubit gates must meet to be advantageous over more conventional entangling strategies. The methodology allows different entangling strategies to be compared without being tied to a specific algorithm, making it applicable to a wide range of quantum tasks.

The results provide a framework to guide the design of future trapped-ion devices: instead of assuming that more complexity in the gate set equals more computational power, the analysis points to concrete performance thresholds that multiqubit gates must exceed to justify their implementation. The toolset developed is available as a starting point for evaluating other architectures and gate sets as the technology advances.