  In this paper we study the stochastic quantization problem on the two
dimensional torus and establish ergodicity for the solutions. Furthermore, we
prove a characterization of the $\Phi^4_2$ quantum field on the torus in terms
of its density under translation. We also deduce that the $\Phi^4_2$ quantum
field on the torus is an extreme point in the set of all $L$-symmetrizing
measures, where $L$ is the corresponding generator.
