Ultrafast Spectroscopy & Quantum Dynamics

Exploring the bright and the dark is the origin of great stories. In the Wang Lab, we investigate crucial photophysics of functional materials upon femtoseconds (10-15 s) after initial excitation and follow the dynamics of excited species through femtosecond to microsecond timescale. This spectroscopic technique allows us to explore the properties of the bright and dark excited states, including coupling between different excited states and their surrounding environments, energy relaxation and transfer pathways, and transfer timescales.

We combine time-resolved spectroscopies that have ultrafast temporal resolution with microscopies that exhibit nanometer spatial resolution. This approach offers unique opportunities to resolve the properties of coherence, spin, and energy transport of these functional materials at the individual nanostructure level.

The fundamental photophysics of what we learn can be translated into novel strategies for bridging chemistry with device designs for renewable energy and quantum applications.

Select Publications

Wang, L.; Allodi, M. A.; Engel, G. S. Quantum coherences reveal excited-state dynamics in biophysical systems. Nat. Rev. Chem. 2019, 3, 477–490

⭐ Featured in Nature Chemistry News & Views: Turner, D. B. Energy transfer: Resonance is the key for coherence. Nat. Chem. 2017, 9, 196–197.

Wang, L.; Griffin, G. B.; Zhang, A.; Zhai, F.; Williams, N. E.; Jordan, R. F.; Engel, G. S. Controlling quantum-beating signals in 2D electronic spectra by packing synthetic heterodimers on single-walled carbon nanotubes. Nat. Chem. 2017, 9, 219–225.

Otto, J. P.*; Wang, L.*; Pochorovski, I.; Blau, S. M.; Aspuru-Guzik, A.; Bao, Z.; Engel, G. S.; Chiu, M. Disentanglement of excited-state dynamics with implications for FRET measurements: two-dimensional electronic spectroscopy of a BODIPY-functionalized cavitand. Chem. Sci. 2018, 9, 3694–3703. *These authors contributed equally.

Wood, R. E.; Lloyd, L. T.; Mujid, F.; Wang, L.; Allodi, M. A.; Gao, H.; Mazuski, R.; Ting, P.-C.; Xie, S.; Park, J.; Engel, G. S. Evidence for the dominance of carrier-induced band gap renormalization over biexciton formation in cryogenic ultrafast experiments on MoS2 monolayers. J. Phys. Chem. Lett. 2020, 11, 2658–2666.