Quantum dynamics of molecular systems involves not only the simple coherent evolution of the system, but also how the molecules couple to their surroundings. Simple approximations such as Förster theory capture dynamics of molecules in solvent quite well. However, as electronic coupling gets stronger and the coupling to the bath becomes weaker, this approach breaks down. While theoretical methods such as Redfield theory can operate in this regime, a structured, shared bath can lead to vibronic coupling, coherent transport and other exciting new dynamical effects. We create spectroscopies, theoretical frameworks, and molecular systems to test these ideas. We translate these notions into new materials and new strategies for harnessing excited state dynamics for quantum communication, information processing, and light harvesting.
L. Wang, N.E. Williams, E.W. Malachosky, J.P. Otto, D. Hayes, R.E. Wood, P. Guyot-Sionnest, and G.S. Engel, "Scalable Ligand-Mediated Transport Synthesis of Organic-Inorganic Hybrid Perovskite Nanocrystals with Resolved Electronic Structure and Ultrafast Dynamics" ACS Nano 11, 2689–2696 2017.
Y. Zhang, A. Wirthwein, F.H. Alharbi, G.S. Engel, and S. Kais., "Dark states enhance the photocell power via phononic dissipation" Phys. Chem. Chem. Phys. 18, 31845-31849 2016.
M.L. Flanagan, P.D. Long, P.D. Dahlberg, B.S. Rolczynski, S.C. Massey, and G.S. Engel, "Mutations to R. sphaeroides Reaction Center Perturb Energy Levels and Vibronic Coupling but Not Observed Energy Transfer Rates" J. Phys. Chem. A 120, 1479-1487 2016.
P.D. Dahlberg, G.J. Norris, C. Wang, S. Viswanathan, V.P. Singh, and G.S. Engel , "Communication: Coherences observed in vivo in photosynthetic bacteria using two-dimensional electronic spectroscopy" J. Chem. Phys. 143, 101101 2015.
V. P. Singh, M. Westberg, C. Wang, P. D. Dahlberg, T. Gellen, A. T. Gardiner, R. J. Cogdell, and G. S. Engel, "Towards quantification of vibronic coupling in photosynthetic antenna complexes" J. Chem. Phys. 142, 212446 2015.