Experimental comparison of two quantum computing architectures

TLDR

The study compares a publicly accessible superconducting transmon device with limited connectivity to a fully connected trapped‑ion system. We run a selection of algorithms on two state‑of‑the‑art 5‑qubit quantum computers based on different technology platforms, programming them in a hardware‑agnostic way to enable identical algorithm comparisons. Algorithms that exploit higher connectivity perform better on the fully connected trapped‑ion system, highlighting the importance of qubit connectivity and gate expressivity, and suggesting that co‑designing applications with hardware will be crucial for future quantum computing success.

Abstract

We run a selection of algorithms on two state-of-the-art 5-qubit quantum computers that are based on different technology platforms. One is a publicly accessible superconducting transmon device with limited connectivity, and the other is a fully connected trapped-ion system. Even though the two systems have different native quantum interactions, both can be programmed in a way that is blind to the underlying hardware, thus allowing the first comparison of identical quantum algorithms between different physical systems. We show that quantum algorithms and circuits that employ more connectivity clearly benefit from a better connected system of qubits. While the quantum systems here are not yet large enough to eclipse classical computers, this experiment exposes critical factors of scaling quantum computers, such as qubit connectivity and gate expressivity. In addition, the results suggest that co-designing particular quantum applications with the hardware itself will be paramount in successfully using quantum computers in the future.