Research

Non-adiabatic dynamics in the presence of a quantized electric field

Many exciting features emerge when the interaction of light with matter is treated quantum mechanically. In the weak-coupling regime, the quantum nature of light leads to fluorescence processes. While in the strong-coupling regime, as is present in optical cavities or plasmonic arrays, new hybridized quantum states are formed comprised of mixtures of the quantum states of light and matter. This mixing can significantly alter the efficiency and outcome of chemical processes. We are developing new quantum-dynamical methods that can readily be combined with classical sampling techniques to directly simulate the non-adiabatic dynamics of chemical systems coupled to quantum light.

 

Charge transport in novel material systems

We are actively exploring charge transport processes in new material systems exhibiting novel photochemical properties. In many cases, conventional theories are insufficient to describe the charge transport mechanism, due to the unique behavior of the surrounding nuclear or electronic environment. To tackle this lack of understanding, we utilize a multi-tiered simulation approach consisting of rare-event sampling techniques, path integral molecular dynamics, and innovative real-time electronic structure methods. Current materials of interest include 3D and 2D perovskites.

 

 

Surface chemistry in the thermodynamic limit

Surfaces play an integral role across chemistry, physics, and biology, appearing in phenomena as diverse as heterogenous catalysis and transport through mesoscopic devices. Yet the accurate simulation of a surface in the true thermodynamic limit presents an outstanding and significant challenge. The difficulty arises that in the thermodynamic limit, the system is non-periodic, but infinite in the direction perpendicular to the surface. To overcome this challenge, we are developing general electronic structure methods, including embedding and Green’s function based approaches, to calculate the properties of a surface in the true thermodynamic limit. We are interested in applying such methodology to investigate the competing mechanisms governing enhanced surface spectroscopies.