Eur. Phys. J. B (2012) 85: 98
https://doi.org/10.1140/epjb/e2012-20864-1

Regular Article

Effects of delayed nonlinear response on wave packet dynamics in one-dimensional disordered chains

¹ Department of Physics and Institute of Theoretical Physics, Nanjing Normal University, Nanjing 210046, P.R. China
² Jiangsu Key Laboratory for Numerical Simulation of Large Scale Complex Systems, Nanjing Normal University, Nanjing 210046, P.R. China

^a e-mail: pqtong@njnu.edu.cn

Received: 25 October 2011
Received in final form: 4 January 2012
Published online: 21 March 2012

Abstract

We study numerically the spreading of an initially localized wave packet in a one-dimensional uncorrelated disordered chain with a nonadiabatic electron-phonon interaction. The nonadiabatic electron-phonon coupling is taken into account in the time-dependent Schrödinger equation by a delayed cubic nonlinearity. In the adiabatic regime, Anderson localization is destroyed and a subdiffusive spreading of wave packet takes place by moderate nonlinearity. In the nonadiabatic regime, the dynamical behavior becomes obviously different. We find that short delay time suppresses delocalization strongly. However, large delay time gives a stronger exponent of spreading. An explanation of this delay induced effect is also discussed.