An external link to the paper is here.
The DOI is 10.1088/1367-2630/9/6/205
They use a few terms as if we all know what they mean, but I did not so I will try to summarize them here
Prisoner’s Dilemma - This game is described well on wikipedia here
zero sum game - This is a game where the one players losses or gains are canceled by the others. The game discussed in this paper is a non zero sum game which means that there is the possibility that if the players were able to work together they could gain more benefit than acting only in their own best interest.
Nash equilibrium - This is a state in a game like Prisoner’s Dilemma where the players each knows the way each other player will act (rat out the other) and therefore will choose this action as well because only all players changing their response together will benefit any of them. This leads to an equilibrium which is not the optimal final state as far as the players are concerned.
Hadamard Gate - is a quantum gate which when acting on a single qbit in a pure state puts it into a superposition.
CPhase gate - This gate flips the phase of the 1, 1 state of the 2 qbits by pi. This weakly entangles the 2 qbits.