  We study the long time behavior of the stochastic quantization equation.
Extending recent results by Mourrat and Weber we first establish a strong
non-linear dissipative bound that gives control of moments of solutions at all
positive times independent of the initial datum. We then establish that
solutions give rise to a Markov process whose transition semigroup satisfies
the strong Feller property. Following arguments by Chouk and Friz we also prove
a support theorem for the laws of the solutions. Finally all of these results
are combined to show that the transition semigroup satisfies the Doeblin
criterion which implies exponential convergence to equilibrium.
  Along the way we give a simple direct proof of the Markov property of
solutions and an independent argument for the existence of an invariant measure
using the Krylov-Bogoliubov existence theorem. Our method makes no use of the
reversibility of the dynamics or the explicit knowledge of the invariant
measure and it is therefore in principle applicable to situations where these
are not available, e.g. the vector-valued case.
