The influence of Anderson localization on the mode decay of excited nonlinear systems

A one-dimensional system of masses with nearest-neighbor interactions and periodic boundary conditions is used to study mode decay and ergodicity in nonlinear, disordered systems. The system is given an initial periodic displacement, and the total system energy within a specific frequency channel is measured as a function of time. Results indicate that the rate of mode decay at early times increases when impurities are added. However, for long times the rate of mode decay decreases with increasing impurity mass and impurity concentration. This behavior at long times can be explained by Anderson localization effects and the nonergodic response of the system.