Amplitude scaling behavior of low-energy Frenkel exciton chains with correlated off-diagonal disorder

TL;DR

This paper investigates how correlated off-diagonal disorder affects the amplitude scaling and localization properties of low-energy Frenkel exciton chains, revealing deviations from typical Dyson singularities and confirming theoretical predictions.

Contribution

It demonstrates the impact of correlated disorder on exciton chain spectra and confirms the scaling behavior predicted by a theory for Dirac fermions with random mass.

Findings

Scaling behavior matches theoretical predictions near the band center.

Correlation causes deviations from Dyson-type spectral singularities.

The concentration dependence of scaling amplitudes is established.

Abstract

We report the amplitude scaling behavior of Frenkel exciton chains with nearest-neighbor correlated off-diagonal random interactions. The band center spectrum and its localization properties are investigated through the integrated density of states and the inverse localization length. The correlated random interactions are produced through a binary sequence similar to the interactions in spin glass chains. We produced sets of data with different interaction strength and "wrong" sign concentrations that collapsed after scaling to the predictions of a theory developed earlier for Dirac fermions with random-varying mass. We found good agreement as the energy approaches the band center for a wide range of concentrations. We have also established the concentration dependence of the lowest order expansion coefficient of the scaling amplitudes for the correlated case. The correlation causes unusual behavior of the spectra, i.e., deviations from the Dyson-type singularity.