Electronic absorption spectra from off-diagonal quantum master equations.

Area of Science:

• Quantum dynamics
• Molecular spectroscopy
• Computational chemistry

Background:

• Quantum master equations (QMEs) describe molecular electronic dynamics.
• Off-diagonal QMEs (OD-QMEs) are useful but present challenges in obtaining Schrödinger picture coherences.
• Accurate electronic coherences are vital for calculating absorption spectra.

Purpose of the Study:

• To propose and validate a method for calculating electronic absorption spectra using OD-QMEs.
• To extract Schrödinger picture electronic coherences from interaction picture dynamics generated by OD-QMEs.
• To assess the accuracy of this method against established techniques.

Main Methods:

• Utilized a novel procedure to extract Schrödinger picture electronic coherences from interaction picture inputs.
• Calculated electronic absorption spectra using both time-local and time-nonlocal OD-QMEs.
• Compared results with a Redfield-type QME and hierarchical equations of motion (HEOM).

Main Results:

• The proposed method successfully calculates electronic absorption spectra from OD-QME dynamics.
• Spectra derived from OD-QMEs show good agreement with reference methods.
• The study validates the extraction procedure for obtaining accurate coherences.

Conclusions:

• The developed method provides a reliable pathway to compute electronic absorption spectra from OD-QMEs.
• This work bridges the gap between OD-QME dynamics and experimentally relevant spectral information.
• The findings enhance the utility of OD-QMEs in studying molecular electronic properties.