Disorder-induced Purcell enhancement in nanoparticle chains

TL;DR

This study numerically investigates how positional disorder in plasmonic nanoparticle chains causes a Dyson singularity in the density of states, leading to disorder-induced Purcell enhancement with potential applications in lasers and spectroscopy.

Contribution

It demonstrates that positional disorder induces a Dyson singularity in the density of states, enabling Purcell enhancement in nanoparticle chains, a novel insight for plasmonic and resonant systems.

Findings

Positional disorder creates a peak in the density of resonant states.

The peak corresponds to Dyson singularity in disordered structures.

Disorder-induced Purcell enhancement can be applied in lasers and SERS.

Abstract

In this paper we report on numerical study of plasmonic nanoparticle chains with long-range dipole-dipole interaction. We have shown that introduction of positional disorder gives a peak in the density of resonant states (DOS) at the frequency of individual nanoparticle resonance. This peak is referred to Dyson singularity in one-dimensional disordered structures [Dyson F., 1953] and, according to our calculations, governs the spectral properties of local DOS. This provides disorder-induced Purcell enhancement that can found its applications in random lasers and for SERS spectroscopy. We stress that this effect relates not only to plasmonic nanoparticles but to an arbitrary chain of nanoparticles or atoms with resonant polarizabilities.