Absorption spectra of quantum aggregates interacting via long-range forces

Area of Science:

• Quantum mechanics
• Spectroscopy
• Condensed matter physics

Background:

• Quantum aggregates exhibit complex absorption spectra due to inter-monomer interactions.
• Understanding these spectra is crucial for applications in quantum computing and sensing.
• Existing models often struggle to incorporate spectral broadening effects accurately.

Purpose of the Study:

• To develop a simple, broadly applicable formula for calculating the absorption spectrum of quantum aggregates.
• To explicitly include spectral broadening in the theoretical framework.
• To validate the formula against theoretical calculations and experimental data.

Main Methods:

• Derivation of a formula relating aggregate spectra to monomer spectra.
• Inclusion of dipole-dipole interactions and spectral broadening.
• Comparison with exact diagonalization of Hamiltonians and experimental results.

Main Results:

• A straightforward formula accurately predicts aggregate absorption spectra from monomer spectra.
• The formula explicitly accounts for spectral broadening, enhancing its practical utility.
• Analytic results reveal a strong dependence of aggregate spectra on monomer broadening characteristics.

Conclusions:

• The presented formula offers a significant simplification for predicting quantum aggregate spectra.
• The inclusion of spectral broadening makes the formula applicable to diverse real-world scenarios.
• The findings are validated by comparison with rigorous theoretical methods and experimental observations.