  Quantum generalizations of conventional games broaden the range of available
strategies, which can help improve outcomes for the participants. With many
players, such quantum games can involve entanglement among many states which is
difficult to implement, especially if the states must be communicated over some
distance. This paper describes a quantum mechanism for the economically
significant $n$-player public goods game that requires only two-particle
entanglement and is thus much easier to implement than more general quantum
mechanisms. In spite of the large temptation to free ride on the efforts of
others in this game, two-particle entanglement is sufficient to give near
optimal expected payoff when players use a simple mixed strategy for which no
player can benefit by making different choices. This mechanism can also address
some heterogeneous preferences among the players.
