Maizelis Z. Propagation, interaction and decoherence of modes in nonlinear quantum systems

The Doctoral Thesis presents the results of the study of the propagation, interaction, attenuation, and decoherence of modes in nonlinear quantum systems with a finite number of degrees of freedom, taking into account the interaction with the external thermostat, sources of additive and phase noises, in 1D and 2D crystal systems and in highly anisotropic layered superconductor plates. In particular, method for separating the effects of frequency and additive noise, as well as finding the characteristics of frequency noise, is proposed. It not only allows to detect and get rid of these noises, but also to determine the state of the system with which the vibration system interacts, according to its response to external excitation. The theory of multistability of states of forced oscillations of a vibrational system dispersively connected with a quantum two-level system is constructed. For argumental oscillations of the classical system, for which multistability is due to a special connection with the external field, the probability distribution function is investigated. It is shown that the effect of zero oscillations of vacuum on the interaction of bodies can be used to analyze their dielectric properties. The negative effect of this effect on the spectroscopy of atoms in a hollow fiber has been studied. The propagation and interaction of modes in low-dimensional systems, as well as in layered superconductors, where the excitation of localized modes leads to a number of important effects have been studied.