Impact of Loss Mechanisms on Linear Spectra of Excitonic and Polaritonic Aggregates

TL;DR

This paper uses the PILD method to analyze how empirical loss mechanisms influence the spectra of excitonic and polaritonic systems, revealing complex, state-dependent effects and the first numerical study of chiral aggregate CD spectra in cavities.

Contribution

It introduces the application of the PILD method to study loss effects on spectra of chiral aggregates and polaritons, including the first numerical exploration of cavity-confined aggregate CD spectra.

Findings

Loss mechanisms affect system states differently based on symmetry and environment interactions.

The CD spectrum of chiral aggregates in cavities is numerically explored for the first time.

Loss impacts on polaritonic CD spectra are highly site-dependent.

Abstract

The presence of loss mechanisms governed by empirical time-scales affect the dynamics and spectra of systems in profound ways. However, incorporation of these effects and their interaction with the thermal dissipative environments interacting with the system prove to be challenging. We have recently developed the path integral Lindblad dynamics (PILD) method to combine numerically rigorous path integral simulations with Lindblad dynamics to account for such empirical loss mechanisms. In this work, we utilize the PILD method to study the absorption and circular dichroism spectra of chiral molecular aggregates and excitonic polaritons. We demonstrate that the effect of loss on particular states in both systems can differ not just on the basis of the symmetries of the state but also on the basis of complicated "interactions" of the system and the loss mechanism with the dissipative environments. We present probably the first numerical exploration of the CD spectrum of chiral molecular aggregates confined in a cavity. While the CD spectrum of just the excitonic aggregates itself is not amenable to simplistic understanding like the exciton chirality (EC) rule, the CD spectrum of polaritonic molecules is even more complex. Additionally, the impact of empirical loss on the polaritonic CD spectrum seems to be highly site-dependent. The impact of a lossy cavity is qualitatively different from the impact of a molecule that leaks the excitation. We explore some of those effects in depth leveraging the framework of path integral Lindblad dynamics.