Experimental observation of the bifurcation dynamics of an intrinsic localized mode in a driven 1-D nonlinear lattice

TL;DR

This study experimentally investigates how an intrinsic localized mode in a driven 1-D nonlinear lattice undergoes bifurcations, revealing softening phase modes and kinetic transitions as the system approaches critical points.

Contribution

It provides the first experimental observation of bifurcation dynamics and kinetic transitions in intrinsic localized modes within a driven nonlinear lattice.

Findings

Phase mode softens near upper bifurcation point

Amplitude of phase mode increases as bifurcation approaches

Two distinct bifurcation points induce different kinetic transitions

Abstract

Linear response spectra of a driven intrinsic localized mode in a micromechanical array are measured as it approaches two fundamentally different kinds of bifurcation points. A linear phase mode associated with this autoresonant state softens in frequency and its amplitude grows as the upper frequency bifurcation point is approached, similar to the soft mode kinetic transition for a single driven Duffing resonator. A lower frequency bifurcation point occurs when the four-wave-mixing partner of this same phase mode intercepts the top of the extended wave branch, initiating a second kinetic transition process.