Nonlocal Games as Cross-Platform Quantum Benchmarks: Exceeding unconditional classical bounds on trapped-ion processors

TL;DR

This paper demonstrates that trapped-ion quantum processors can outperform classical bounds in nonlocal games, establishing their potential as universal benchmarks for quantum hardware performance across different platforms.

Contribution

First implementation of a graph coloring nonlocal game on trapped-ion processors showing quantum advantage, highlighting nonlocal games as cross-platform quantum benchmarks.

Findings

One trapped-ion system exceeded the classical bound with statistical significance.

Other systems achieved performance comparable to superconducting processors.

First violation of a classical bound in a graph coloring nonlocal game on quantum hardware.

Abstract

Nonlocal games provide application-level benchmarks for quantum hardware whose classical performance bounds are information-theoretic, holding against all classical strategies regardless of computational resources. We implement a 14-vertex graph coloring game, the smallest graph exhibiting a quantum-classical separation for this game type, on four trapped-ion quantum processors across three institutions. One system achieved a win rate that surpasses the classical bound with statistical significance, marking the first violation of a classical bound in a graph coloring nonlocal game on quantum hardware. The remaining systems achieved win rates comparable to the best superconducting processors evaluated on the same game, further illustrating the potential of nonlocal games as cross-architecture quantum benchmarks.