Important Questions

How efficient is excitation energy transfer in photosynthetic complexes and what leads to this efficiency?

We are interested in investigating the photophysics of light harvesting and the structure-function relationship in photosynthetic complexes to obtain insights into the design principles of photosynthesis. Read More.

How do electronic-vibrational and electron-phonon coupling influence excited state dynamics?

An understanding of electronic-vibrational and electron-phonon coupling is essential in order to understand the non-radiative decay pathways of a whole variety of molecular and nanomaterial systems. Read more.

How do vibrations, resonant with the excitonic energy gap, affect the electronic energy transport dynamics?

IR modes, that are resonant with the energy gap between a pair of excitons, could significantly affect the dynamics of electronic energy transport in light-harvesting complexes, possibly resulting in long-lived coherences and faster population relaxation. Read more.

How do spectroscopic measurements represent spatial energy distributions, and the dynamics of nanoscale energy transfer and excitation localization?

The excitonic energy relaxation measured in 2D electronic spectroscopy experiments does not always correspond to the energy transport across a network of pigments, especially when vibrations participate. We are using simulations to predict the phenomena that result from vibrational-electronic mixing in coupled heterodimer systems that are significantly influenced by the biological protein environment. Read More.

How do the structures of photosynthetic pigment-protein complexes and membranes affect the efficiency of light harvesting and photo-protection mechanisms?

Chlorophylls that absorb light and transfer excitations to reaction centers are bound inside proteins. These proteins, in turn, form large networks of pigment-protein complexes that transfer energy both within individual complexes and between complexes and can respond to changes in light conditions. Read More.

How are photosynthetic organisms able to protect themselves from energy-related damage?

Dissipation of excess excitation energy in the light harvesting antenna of Photosystem II gives photosynthetic organisms an evolutionary advantage by reducing damage in fluctuating light conditions. Using experimental and theoretical methods, we are trying to understand the energetic rearrangment that takes place in order to switch on this pathway. Read More.

Does electronic coherence in pigment-protein complexes facilitate energy transfer in photosynthesis?

We are interested in investigating the phenomenon of quantum beating in a pigment-protein complex called FMO in the hopes of learning how long this observed electronic coherence is preserved and what it means for the energy transfer in photosynthetic organisms. Read More.

How does the structure of photosynthetic pigments contribute to their function?

Photosynthetic proteins lock pigments into certain geometries, contributing to their high quantum efficiency by tuning the pigment energies to allow maximum energy flow between them. We are seeking to identify the geometries of carotenoids and chlorophylls in major light harvesting complexes in order to determine the design principles behind the protein’s structure. Read more.