Evolving disorder and chaos enhances the wave speed of elastic waves

Abstract

Static or frozen disorder, characterised by spatial heterogeneities, influences diverse complex systems, encompassing many-body systems, equilibrium and nonequilibrium states of matter, intricate network topologies, biological systems, and wave-matter interactions. While static disorder has been thoroughly examined, delving into evolving disorder brings increased intricacy to the issue. An example of this complexity is the observation of stochastic acceleration of electromagnetic waves in evolving media, where noisy fluctuations in the propagation medium transfer effective momentum to the wave. Here, we investigate elastic wave propagation in a one-dimensional heterogeneous medium with diagonal disorder. We examine two types of complex elastic materials: one with static disorder, where mass density randomly varies in space, and the other with evolving disorder, featuring random variations in both space and time. Our results indicate that evolving disorder enhances the propagation speed of Gaussian pulses compared to static disorder. Additionally, we demonstrate that the enhanced speed effect also occurs when the medium evolves chaotically rather than randomly over time. The latter establishes that evolving randomness is not a unique prerequisite for observing the enhanced transport of wavefronts, introducing the concept of chaotic speed enhancement of waves in complex media.

arXiv commentArticle accepted in Journal of Statistical Mechanics: Theory and Experiment. 21 pages, 5 figures

References in corpus (14)

• Quantum transport simulations in a programmable nanophotonic processor
• Anderson localization in Bose-Einstein condensates
• On the Microscopic Foundations of Elasticity
• Environment-assisted quantum transport in a 10-qubit network
• Transitions among crystal, glass, and liquid in a binary mixture with changing particle size ratio and temperature
• Universal statistics of waves in a random time-varying medium
• Localization of elastic waves in heterogeneous media with off-diagonal disorder and long-range correlations
• Deterministic Brownian Motion: The Effects of Perturbing a Dynamical System by a Chaotic Semi-Dynamical System
• Lyapunov exponents, one-dimensional Anderson localisation and products of random matrices
• The hyperbolic Anderson model: Moment estimates of the Malliavin derivatives and applications
• Effects of nonlinearity on Anderson localization of surface gravity waves
• Hyperdiffusion of quantum waves in random photonic lattices
• Stochastic differential equations driven by deterministic chaotic maps: analytic solutions of the Perron-Frobenius equation
• Multiple scattering theory in one dimensional space and time dependent disorder: Average field