Structural basis of multistationary quantum systems. I. Effective single-particle dynamics

Abstract

The structural basis of multistationarity is discussed on the basis of semiconductor heterostructures on a nanometer scale. It is shown that for an appropriate choice of the system's parameters the microscopic degrees of freedom decouple into ``dynamical'' and ``passive'' degrees of freedom, which in turn give rise to multistationary quasimolecular subsystems. Separation of time scales and the selection rules for the pertinent electronic transitions are shown to be controlled by the localization behavior of the electron wave function and thus, finally, by geometrical and band-gap parameters of the semiconductor heterostructure. Selective coupling of discrete electronic eigenstates via local operators (acoustic phonon, dipole interaction) leads to a ``switching'' dynamics realized by electronic single-particle transitions. Three types of attractors can be distinguished and may be prepared by single modes of the electromagnetic field. The principle uncertainty and the stochastic nature of the quantum-mechanical dynamics are discussed within the context of simple logical operations and the storage of information in quantum systems.