Calculations of coherent two-dimensional electronic spectra using forward and backward stochastic wavefunctions

Area of Science:

• Quantum dynamics
• Spectroscopy
• Computational chemistry

Background:

• The optical response function formalism is a well-established framework for studying molecular systems.
• Accurate computation of two-dimensional (2D) electronic spectra is crucial for understanding quantum dynamics.

Purpose of the Study:

• To present a novel computational strategy for obtaining 2D electronic spectra.
• To demonstrate the validity and efficiency of the proposed method.
• To investigate the role of environmental factors in quantum coherence.

Main Methods:

• Employing forward-backward stochastic Schrödinger equations in a segmented manner.
• Utilizing an excitonically coupled dimer model system for validation.
• Comparing results against deterministic hierarchy equations of motion and quantum master equations.

Main Results:

• The proposed stochastic method accurately computes 2D electronic spectra.
• Environmental characteristic frequency significantly regulates oscillating signal lifetimes and quantum coherence.
• The stochastic approach offers substantial reduction in numerical cost compared to existing methods.

Conclusions:

• The novel stochastic Schrödinger equation approach provides an efficient and accurate tool for 2D electronic spectroscopy.
• Understanding environmental dynamics is key to controlling quantum coherence in molecular systems.
• This method has potential for studying quantum effects in large-scale photosynthetic systems.