Dynamic Localization of Particle Moving in Solid Film

Calculation of the density matrix (DM) for a projectile during the passage through a solid film have shown progressive diminishing of the projectile's coherence length. For to find a more detail information about the projectile we perform a famous von Newmann's decomposition of DM on ``pure'' states and find an ambiguity of this approach. The unambiguous decomposition can be obtained if we introduce an additional coherence criterion: each term of the decomposition should conserve the shape of function of coherence. We use the next arguments: i) the function of coherence could be measured; ii) the parts of a wave field found in relation of mutual coherence belong to one particle and couldn't be separated from the particle; iii) the parts of a wave field which don’t find in relation of mutual coherence are belong to different particles and couldn't be associated with one particle. With the help of this approach one can find that during the penetration in a film the projectile undergo a significant spatial localization. The localized quasi-stationary state of projectile could conserve the information about the past interaction with environment.