Modulational instability and resonant wave modes act on the metastability of oscillator chains

TL;DR

This paper investigates how modulational instability and resonant wave modes influence the metastability and escape dynamics of a two-dimensional oscillator chain in a complex potential landscape, revealing noise-free escape mechanisms.

Contribution

It provides analytical insights into the role of breather and resonant wave modes in metastability and escape processes in oscillator chains with complex potentials.

Findings

Different dynamical regimes dominated by wave modes identified

Metastable states can be escaped via nonlinear cooperative effects without noise

Fast noise-free escape is possible even at low energies

Abstract

We describe the emergence and interactions of breather modes and resonant wave modes within a two-dimensional ring-like oscillator chain in a microcanonical situation. Our analytical results identify different dynamical regimes characterized by the potential dominance of either type of mode. The chain is initially placed in a meta-stable state which it can leave by passing over the brim of the applied Mexican-hat-like potential. We elucidate the influence of the different wave modes on the mean-first passage time. A central finding is that also in this complex potential landscape a fast noise-free escape scenario solely relying on nonlinear cooperative effects is accomplishable even in a low energy setting.