In bi-matrix games the Bishop-Cannings theorem of the classical evolutionary
game theory does not permit pure evolutionarily stable strategies (ESSs) when a
mixed ESS exists. We find the necessary form of two-qubit initial quantum
states when a switch-over to a quantum version of the game also changes the
evolutionary stability of a mixed symmetric Nash equilibrium.Comment: 8 pages, no figure, to appear in Communications in Theoretical
Physic
