Nonlocality and conflicting interest games

TL;DR

This paper demonstrates that quantum nonlocality can provide an advantage in conflicting interest games, showing both theoretical and experimental evidence of improved payoffs over classical strategies.

Contribution

It introduces a new conflicting interest game where quantum strategies outperform classical ones and provides experimental validation using entangled photons.

Findings

Quantum strategies outperform classical in the game.

Existence of a fair quantum equilibrium with higher payoffs.

Experimental demonstration of quantum advantage with entangled photons.

Abstract

Nonlocality enables two parties to win specific games with probabilities strictly higher than allowed by any classical theory. Nevertheless, all known such examples consider games where the two parties have a common interest, since they jointly win or lose the game. The main question we ask here is whether the nonlocal feature of quantum mechanics can offer an advantage in a scenario where the two parties have conflicting interests. We answer this in the affirmative by presenting a simple conflicting interest game, where quantum strategies outperform classical ones. Moreover, we show that our game has a fair quantum equilibrium with higher payoffs for both players than in any fair classical equilibrium. Finally, we play the game using a commercial entangled photon source and demonstrate experimentally the quantum advantage.