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Updated: Nov 8, 2025
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Excitonic Hamiltonians for Calculating Optical Absorption Spectra and Optoelectronic Properties of Molecular Aggregates and Solids
Published on: May 27, 2020
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Anisotropy in fifth-order exciton-exciton-interaction two-dimensional spectroscopy
Julian Lüttig1, Tobias Brixner1, Pavel Malý1
1Institut für Physikalische und Theoretische Chemie, Am Hubland, 97074 Würzburg, Germany.
The Journal of Chemical Physics
|April 23, 2021
Summary
Exciton-exciton-interaction two-dimensional (EEI2D) spectroscopy reveals how geometry impacts exciton transport. Measuring anisotropy in EEI2D spectra helps identify structural effects in molecular systems and polymers.
Area of Science:
- Quantum dynamics
- Spectroscopy
- Materials science
Background:
- Exciton transport is crucial for energy transfer in molecular systems and polymers.
- Geometrical and energetic landscapes significantly influence exciton transport dynamics.
- Perturbations like molecular orientation, disorder, kinks, and domains affect exciton diffusion.
Purpose of the Study:
- To investigate the anisotropy in Exciton-Exciton-Interaction two-dimensional (EEI2D) spectroscopy.
- To develop an efficient theoretical approach for calculating anisotropy using the response-function formalism.
- To demonstrate how EEI2D anisotropy can identify geometrical effects on exciton transport.
Main Methods:
- Developed a general approach to calculate anisotropy in EEI2D spectroscopy.
- Employed a Frenkel exciton model with Redfield-theory dynamics for numerical simulations.
- Analyzed anisotropy in dimers, molecular heterodimers, and extended conjugated polymers.
Main Results:
- Demonstrated that EEI2D anisotropy can identify geometrical effects on exciton transport in dimers and polymers.
- Showcased the utility of EEI2D anisotropy in distinguishing dynamic localization and annihilation in a molecular heterodimer.
- Identified anisotropy changes as a unique signature for exciton transport between differently oriented polymer sections.
Conclusions:
- Anisotropy in EEI2D spectroscopy is a powerful tool for distinguishing between different molecular and polymer geometries.
- This method provides a deeper understanding of long-range exciton transport influenced by structural variations.
- EEI2D anisotropy analysis can reveal subtle geometrical effects impacting energy transfer processes.
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