TY - JOUR A1 - Mulansky, Mario A1 - Picovsky, Arkady S. T1 - Re-localization due to finite response times in a nonlinear Anderson chain JF - The European physical journal : B, Condensed matter and complex systems N2 - We study a disordered nonlinear Schrodinger equation with an additional relaxation process having a finite response time tau. Without the relaxation term, tau = 0, this model has been widely studied in the past and numerical simulations showed subdiffusive spreading of initially localized excitations. However, recently Caetano et al. [Eur. Phys. J. B 80, 321 (2011)] found that by introducing a response time tau > 0, spreading is suppressed and any initially localized excitation will remain localized. Here, we explain the lack of subdiffusive spreading for tau > 0 by numerically analyzing the energy evolution. We find that in the presence of a relaxation process the energy drifts towards the band edge, which enforces the population of fewer and fewer localized modes and hence leads to re-localization. The explanation presented here relies on former findings by Mulansky et al. [Phys. Rev. E 80, 056212 (2009)] on the energy dependence of thermalized states. Y1 - 2012 U6 - https://doi.org/10.1140/epjb/e2012-21040-5 SN - 1434-6028 VL - 85 IS - 3 PB - Springer CY - New York ER -