Transform-Limited-Pulse Representation of Excitation with Natural Incoherent Light

TL;DR

This paper introduces a wave function formalism to represent natural incoherent light excitation as a collection of deterministic pulses, enabling new computational and experimental approaches to studying molecular systems like photosynthetic complexes.

Contribution

It demonstrates that thermal excitation can be modeled by deterministic pulse realizations, challenging the need for randomness in classical models, and provides a practical framework for analysis and measurement.

Findings

Thermal excitation can be represented by deterministic pulsed realizations.

The formalism facilitates wave function-based calculations of excitation dynamics.

Provides a method for experimental determination of natural incoherent excitation.

Abstract

We study the natural excitation of molecular systems, applicable to, for example, photosynthetic light-harvesting complexes, by natural incoherent light. In contrast with the conventional classical models, we show that the light need not have random character to properly represent the resultant linear excitation. Rather, thermal excitation can be interpreted as a collection of individual events resulting from the system's interaction with individual, deterministic pulsed realizations that constitute the field. The derived expressions for the individual field realizations and excitation events allow for a wave function formalism, and therefore constitute a useful calculational tool to study dynamics following thermal-light excitation. Further, they provide a route to the experimental determination of natural incoherent excitation using pulsed laser techniques.