In this paper we report on a 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 at the frequency of individual nanoparticle resonance. This peak is referred to as Dyson singularity in one-dimensional disordered structures and, according to our calculations, governs the spectral properties of local density of states. This provides disorder-induced Purcell enhancement that can find applications in random lasers and for surface-enhanced Raman-scattering spectroscopy. We stress that this effect relates not only to plasmonic nanoparticles but also to an arbitrary chain of nanoparticles or atoms with resonant polarizabilities.

• Received 28 November 2014
• Revised 26 January 2015

DOI:https://doi.org/10.1103/PhysRevA.91.023821