Computational Polaritonics

1. Cavity molecular dynamics (CavMD)

Expanding the scope of conventional molecular dynamics, CavMD approach can efficiently simulate collective vibrational strong coupling formed by a large collection of realistic molecules. Beyond the single-mode limit, the recently developed mesoscale CavMD approach propagates the coupled light-matter dynamics for condensed-phase molecules confined in a wide range of cavity geometries, such as the planar Fabry—Pérot cavities employed in experiments. 

We are actively examining the boundaries of single-mode and mesoscale CavMD. Please check the Github page for more details.

2. FDTD with auxiliary bath fields (FDTD-Bath)

The finite-difference time-domain (FDTD) algorithm is a popular choice for solving classical Maxwell's equations, with the material response represented by a set of well-defined dielectric functions. While FDTD is widely applied for simulating linear polariton spectroscopy in optical or plasmonic devices, its description of more nuanced nonequilibrium polariton dynamics is not very satisfactory, mostly due to the lack of molecular details with simple dielectric functions. Aiming at enhancing the description of molecular interactions, the FDTD-Bath approach introduces the system-bath Hamiltonian in the FDTD engine. 

Please check the Github page for more details.

3. Reduced semiclassical electrodynamics

The reduced semiclassical electrodynamics approach sits between CavMD and FDTD-Bath. In this approach, the coupled Maxwell–Schrödinger equations are propagated for simulating local molecular processes in a realistic cavity structure under collective strong coupling. Particularly, only a few molecules, referred to as quantum impurities, are treated quantum mechanically, while the remaining macroscopic molecular layer and the cavity structure are modeled using dielectric functions.