Experimental Quantum Advantage in the Odd-Cycle Game

Abstract

We report the first experimental demonstration of the odd-cycle game. We entangle two atoms separated by ∼2m, and the players use them to win the odd-cycle game with a probability ∼26σ above that allowed by the best classical strategy. The experiment implements the optimal quantum strategy, is free of loopholes, and achieves 97.8(3)% of the theoretical limit to the quantum winning probability. We perform the associated Bell test and measure a nonlocal content of 0.54(2)—the largest value for physically separate devices, free of the detection loophole, ever observed. Published by the American Physical Society 2025