Discrete breathers at the interface between a diatomic and monoatomic granular chain

TL;DR

This paper investigates the existence, stability, and dynamics of discrete breathers at the interface of diatomic and monoatomic granular chains, revealing their robustness and conditions for formation.

Contribution

It provides a systematic analysis of interface breathers, highlighting their robustness and the conditions necessary for their nucleation and stability.

Findings

Interface breathers are more robust than bulk diatomic breathers.

Existence of a linear spectral gap is crucial for breather formation.

Minimal excitation conditions for nucleation are identified.

Abstract

In the present work, we develop a systematic examination of the existence, stability and dynamical properties of a discrete breather at the interface between a diatomic and a monoatomic granular chain. We remarkably find that such an "interface breather" is more robust than its bulk diatomic counterpart throughout the gap of the linear spectrum. The latter linear spectral gap needs to exist for the breather state to arise and the relevant spectral conditions are discussed. We illustrate the minimal excitation conditions under which such an interface breather can be "nucleated" and analyze its apparently weak interaction with regular highly nonlinear solitary waveforms.