Slow energy relaxation of macromolecules and nano-clusters in solution

TL;DR

This paper explains slow energy relaxation in nanophysics systems by modeling solvent interactions, showing that inhomogeneous coupling causes complex, non-exponential decay dynamics in molecules and nano-clusters.

Contribution

It introduces a harmonic model demonstrating how solvent coupling inhomogeneity leads to slow, complex relaxation in nanostructures.

Findings

Myoglobin exhibits non-exponential relaxation dynamics.

Metal nano-clusters show similar slow relaxation behavior.

Inhomogeneous solvent coupling explains the relaxation spectrum.

Abstract

Many systems in the realm of nanophysics from both the living and inorganic world display slow relaxation kinetics of energy fluctuations. In this paper we propose a general explanation for such phenomenon, based on the effects of interactions with the solvent. Within a simple harmonic model of the system fluctuations, we demonstrate that the inhomogeneity of coupling to the solvent of the bulk and surface atoms suffices to generate a complex spectrum of decay rates. We show for Myoglobin and for a metal nano-cluster that the result is a complex, non-exponential relaxation dynamics.