Thermal lifetime of breathers

TL;DR

This paper investigates how long localized excitations called breathers persist in nonlinear lattices at finite temperature, revealing that their lifetime grows exponentially with energy, which could help detect breathers experimentally.

Contribution

The study introduces a method to measure breather lifetime using the participation number and demonstrates its exponential increase with energy across various models.

Findings

Breather lifetime increases exponentially with energy.

Significant lifetime increase observed when energy exceeds ten times thermal energy.

Method may enable experimental detection of breathers.

Abstract

In this article, we explore the lifetime of localized excitations in nonlinear lattices, called breathers, when a thermalized lattice is perturbed with localized energy delivered to a single site. We develop a method to measure the time it takes for the system to approach equilibrium based on a single scalar quantity, the participation number, and deduce the value corresponding to thermal equilibrium. We observe the time to achieve thermalization as a function of the energy of the excited site. We explore a variety of different physical system models. The result is that the lifetime of breathers increases exponentially with the breather energy for all the systems. This increase becomes observable when this energy is larger than approximately ten times the local average thermal energy. These results may provide a method to detect the existence of breathers in real systems.