  Two types of arguments concerning (im)possibility of constructing a scalable,
exponentially stable quantum memory equipped with Hamiltonian controls are
discussed. The first type concerns ergodic properties of open Kitaev models
which are considered as promising candidates for such memories. It is shown
that, although the 4D Kitaev model provides stable qubit observables, the
Hamiltonian control is not possible. The thermodynamical approach leads to the
new proposal of the revised version of Landauer's principle and suggests that
the existence of quantum memory implies the existence of the perpetuum mobile
of the second kind. Finally, a discussion of the stability property of
information and its implications is presented.
