Superradiance at the localization-delocalization crossover in tubular chlorosomes

TL;DR

This study investigates how disorder influences spectral properties and excitonic localization in tubular chlorosomes, revealing a size-dependent crossover that enhances superradiance and energy transfer efficiency.

Contribution

It introduces a detailed analysis of disorder effects on spectral and localization properties in chlorosomes, identifying a crossover linked to optimal superradiance.

Findings

Localization-delocalization crossover depends on size and energy.

Superradiant states are located at the crossover energy.

Disorder enhances energy transfer efficiency.

Abstract

We study the effect of disorder on spectral properties of tubular chlorosomes in green sulfur bacteria Cf. aurantiacus. Employing a Frenkel-exciton Hamiltonian with diagonal and off-diagonal disorder consistent with spectral and structural studies, we analyze excitonic localization and spectral statistics of the chlorosomes. A size-dependent localization-delocalization crossover is found to occur as a function of the excitonic energy. The crossover energy region coincides with the more optically active states with maximized superradiance, and is, consequently, more conducive for energy transfer.