  In this mainly survey paper we consider the Lagrangian $ L(x,v) = \frac{1}{2}
\, |v|^2 - V(x) $, and a closed form $w$ on the torus $ \mathbb{T}^n $. For the
associated Hamiltonian we consider the the Schrodinger operator ${\bf
H}_\beta=\, -\,\frac{1}{2 \beta^2} \, \Delta +V$ where $\beta$ is large real
parameter. Moreover, for the given form $\beta\, w$ we consider the associated
twist operator ${\bf H}_\beta^w$. We denote by $({\bf H}_\beta^w)^*$ the
corresponding backward operator. We are interested in the positive
eigenfunction $ \psi_\beta$ associated to the the eigenvalue $ E_\beta$ for the
operator ${\bf H}_\beta^{w} $. We denote $ \psi_\beta^*$ the positive
eigenfunction associated to the the eigenvalue $ E_\beta$ for the operator
$({\bf H}_\beta^{w})^* $. Finally, we analyze the asymptotic limit of the
probability $\nu_\beta= \psi_\beta\, \psi_\beta^*$ on the torus when $\beta \to
\infty$. The limit probability is a Mather measure. We consider Large
deviations properties and we derive a result on Transport Theory. We denote
$L^{-}(x,v) = \frac{1}{2} \, |v|^2 - V(x) - w_x(v) $ and $L^{+}(x,v) =
\frac{1}{2} \, |v|^2 - V(x) + w_x(v) $. We are interest in the transport
problem from $\mu_{-}$ (the Mather measure for $L^{-}$) to $\mu_{+}$ (the
Mather measure for $L^{+}$) for some natural cost function. In the case the
maximizing probability is unique we use a Large Deviation Principle due to N.
Anantharaman in order to show that the conjugated sub-solutions $u$ and $u^*$
define an admissible pair which is optimal for the dual Kantorovich problem.
