Global approximate controllability for Schrödinger equation in higher Sobolev norms and applications

We prove that the Schrödinger equation is approximately controllable in Sobolev spaces Hs, s>0, generically with respect to the potential. We give two applications of this result. First, in the case of one space dimension, combining our result with a local exact controllability property, we get the global exact controllability of the system in higher Sobolev spaces. Then we prove that the Schrödinger equation with a potential which has a random time-dependent amplitude admits at most one stationary measure on the unit sphere S in L2.