Zero-energy peak of the density of states and localization properties of a one-dimensional Frenkel exciton: Off-diagonal disorder

TL;DR

This paper investigates the zero-energy peak in the density of states of a one-dimensional Frenkel exciton with off-diagonal disorder, revealing that the peak is caused by localized states and comparing different coupling models.

Contribution

It provides new insights into the nature of the zero-energy peak and the localization properties of excitonic states in disordered one-dimensional systems.

Findings

The zero-energy peak is caused by localized states.

Localized states dominate near the zero-energy peak.

Comparison shows differences between nearest-neighbor and long-range coupling models.

Abstract

We study a one-dimensional Frenkel Hamiltonian with off-diagonal disorder, focusing our attention on the physical nature of the zero-energy peak of the density of states. The character of excitonic states (localized or delocalized) is also examined in the vicinity of this peak. It is shown that the state being responsible for the peak is localized. A detailed comparison of the nearest-neighbor approach with the long-range dipole-dipole coupling is performed.