Control of wavepacket spreading in nonlinear finite disordered lattices

Abstract

In the absence of nonlinearity all normal modes (NMs) of a chain with disorder are spatially localized (Anderson localization). We study the action of nonlinearity, whose strength is ramped linearly in time. It leads to a spreading of a wavepacket due to interaction with and population of distant NMs. Eventually the nonlinearity induced frequency shifts take over, and the wavepacket becomes selftrapped. On finite chains a critical ramping speed is obtained, which separates delocalized final states from localized ones. The critical value depends on the strength of disorder and is largest when the localization length matches the system size.

7 pages, 4 figures, submitted to PRE

References in corpus (5)

• Direct observation of Anderson localization of matter-waves in a controlled disorder
• Destruction of Anderson localization by a weak nonlinearity
• Universal spreading of wavepackets in disordered nonlinear systems
• Absence of Wavepacket Diffusion in Disordered Nonlinear Systems
• q-breathers in Discrete Nonlinear Schroedinger lattices