Spontaneously localized electron states in a discrete anisotropic two-dimensional lattice

Spontaneously localized electron states are investigated numerically in a d iscrete anisotropic two-dimensional phonon lattice taking into account the electron-phonon interactions. Such a lattice is used as a model of the quas i-one-dimensional compounds, in the range of parameters characteristic of c onjugated polymers, for which the interchain interactions are taken into ac count. It is shown that for certain ranges of parameters, there are soliton -like static solutions that correspond to fully delocalized electron states or to the very localized small polaron states. We show that the solutions of the first type are stable under small perturbations and we also analyze numerically their behaviour under relatively strong perturbations. (C) 2000 Elsevier Science B.V. All rights reserved.