2014/11/30 by Alejandro J. Martínez, P. G. Kevrekidis, Mason A. Porter · 1 citation
Engineering · Mathematics · Physics and Astronomy · #Condensed matter physics #Energy transport #Engineering physics #Materials science #Nonlinear Photonic Systems #Numerical methods in engineering #Physics #Statistical physics #Topological Materials and Phenomena #cond-mat.dis-nn #cond-mat.stat-mech #math-ph #math.MP #nlin.CD #nlin.PS
paper · pdf · doi:10.1103/physreve.93.022902
published as Phys. Rev. E 93, 022902 (2016) · 23 pages, 11 figures; the abstract in this website field is a shortened version of the paper's full abstract because of spatial limits
arxiv created 2015/09/11 · openalex publication_date 2016/02/12 · arxiv updated 2016/02/17 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/06
We study the spreading of initially localized excitations in one-dimensional disordered granular crystals. We thereby investigate localization phenomena in strongly nonlinear systems, which we demonstrate to differ fundamentally from localization in linear and weakly nonlinear systems. We conduct a thorough comparison of wave dynamics in chains with three different types of disorder---an uncorrelated (Anderson-like) disorder and two types of correlated disorders (which are produced by random dimer arrangements)---and for two types of initial conditions (displacement excitations and velocity excitations). We find for strongly precompressed (i.e., weakly nonlinear) chains that the dynamics depend strongly on the type of initial condition. In particular, for displacement excitations, the long-time asymptotic behavior of the second moment \stackrel\ifmmode \else \~\fim2 of the energy has oscillations that depend on the type of disorder, with a complex trend that differs markedly from a power law and which is particularly evident for an Anderson-like disorder. By contrast, for velocity excitations, we find that a standard scaling \stackrel\ifmmode \else \~\fim2\ensuremath∼t^\ensuremathγ (for some constant \ensuremathγ) applies for all three types of disorder. For weakly precompressed (i.e., strongly nonlinear) chains, \stackrel\ifmmode \else \~\fim2 and the inverse participation ratio P^\ensuremath-1 satisfy scaling relations \stackrel\ifmmode \else \~\fim2\ensuremath∼t^\ensuremathγ and P^\ensuremath-1\ensuremath∼t^\ensuremath-\ensuremathη, and the dynamics is superdiffusive for all of the cases that we consider. Additionally, when precompression is strong, the inverse participation ratio decreases slowly (with \ensuremathη<0.1) for all three types of disorder, and the dynamics leads to a partial localization around the core and the leading edge of a propagating wave packet. For an Anderson-like disorder, displacement perturbations lead to localization of energy primarily in the core, and velocity perturbations cause the energy to be divided between the core and the leading edge. This localization phenomenon does not occur in the sonic-vacuum regime, which yields the surprising result that the energy is no longer contained in strongly nonlinear waves but instead is spread across many sites. In this regime, the exponents are very similar (roughly \ensuremathγ\ensuremath≈1.7 and \ensuremathη\ensuremath≈1) for all three types of disorder and for both types of initial conditions.