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Updated: Aug 5, 2026
08:04
Excitonic Hamiltonians for Calculating Optical Absorption Spectra and Optoelectronic Properties of Molecular Aggregates and Solids
Published on: May 27, 2020
Unified First-Principles Formula for Time-Resolved ARPES Spectra of Coherent and Incoherent Excitons beyond the
Gianluca Stefanucci1, Enrico Perfetto1
1INFN, Sezione di Roma Tor Vergata, Università di Roma Tor Vergata, Dipartimento di Fisica, Via della Ricerca Scientifica 1, 00133 Rome, Italy and , Via della Ricerca Scientifica 1, 00133 Rome, Italy.
Physical Review Letters
|July 26, 2026
Summary
Researchers developed a unified framework to interpret exciton effects on electronic band structures using time-resolved photoemission spectroscopy. This method links exciton dynamics to observable sidebands, offering a predictive tool for complex materials.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Spectroscopy
Background:
- Experimental techniques like time-resolved and angle-resolved photoemission spectroscopy have advanced significantly.
- A quantitative, microscopic framework for interpreting exciton-induced modifications of electronic band structures is lacking, especially beyond the low-density limit.
Purpose of the Study:
- To develop a unified theoretical approach for interpreting exciton dynamics and their impact on electronic band structures.
- To provide a first-principles formula for time-resolved photoemission spectra applicable across various experimental conditions.
Main Methods:
- Introduction of a unified theoretical framework.
- Linking coherent and incoherent exciton dynamics to experimentally observable excitonic sidebands.
- Derivation of a general, first-principles formula for time-resolved photoemission spectra.
Main Results:
- A unified approach connecting exciton dynamics (coherent and incoherent) to distinct excitonic sidebands is established.
- A general formula for time-resolved photoemission spectra is derived.
- The framework is applicable across a broad range of temperatures, excitation densities, and pump-probe delays.
Conclusions:
- The developed framework provides a quantitative, microscopic understanding of exciton-induced band structure modifications.
- This advance offers a predictive tool for tracking excitonic dynamics in complex materials.
- The approach is valid beyond the low-density limit and across diverse experimental parameters.
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