Eur. Phys. J. B (2012) 85: 7
https://doi.org/10.1140/epjb/e2011-20358-8

Regular Article

Self-trapping of interacting electrons in crystalline nonlinear chains

Instituto de Física, Universidade Federal de Alagoas, Maceió AL 57072-970, Brazil

^a e-mail: fidelis@if.ufal.br

Received: 10 May 2011
Received in final form: 22 September 2011
Published online: 11 January 2012

Abstract

Considering the nonlinearity arising from the interaction between electrons and lattice vibrations, an effective electronic model with a self-interaction cubic term is employed to study the interplay between electron-electron and electron-phonon interactions. Based on numerical solutions of the time-dependent nonlinear Schroedinger equation for an initially localized two-electron singlet state, we show that the magnitude of the electron-phonon coupling χ necessary to promote the self-trapping of the electronic wave packet decreases as a function of the electron-electron interaction U. We show that such dependence is directly linked to the narrowing of the band of bounded two-electron states as U increases. We obtain the transition line in the χ × U parameter space separating the phases of self-trapped and delocalized electronic wave packets. The present results indicates that nonlinear contributions plays a relevant role in the electronic wave packet dynamics, particularly in the regime of strongly correlated electrons.