The Engel Group at The University of Chicago

News from The Engel Group at The University of Chicago

New Graduate Students 11/17/2025

Welcome to Advait Risbud, Xander Wilcox, and Brayden Banks, Jack Callahan, and Gabriel Levine who are joining the group as Graduate Student Researchers.

New Graduate Student Rotator 10/1/2025

Welcome to Qirui Wang, who is joining the group as a graduate student rotator.

New Graduate Student Rotators 9/2/2025

Welcome to Xander Wilcox and Brayden Banks, who are joining the group as graduate student rotators.

New Graduate Student Rotator 7/28/2025

Welcome to Juho Kim, who is joining the group as a summer graduate student rotator.

New Graduate Student Rotators 7/14/2025

Welcome to Advait Risbud, Gabriel Levine, and Jack Callahan, who are joining the group as summer graduate student rotators.

Paper Published 7/1/2025

Congratulations to Coco Li and our collaborators in the Alivisatos group on having their paper entitled, "Efficient Up-Conversion in CsPbBr₃ Nanocrystals via Phonon-Driven Exciton-Polaron Formation" published in Nature Communications.

More News

Specific Research Areas in The Engel Group

Research area: Quantum Biology

We seek to understand how biological systems exploit quantum mechanical phenomena. For example, photosynthetic antenna complexes use coherent energy transfer to move energy with extreme efficiency despite a dynamic, disordered environment. We use femtosecond laser systems to probe energy transfer on ultrafast timescales in an attempt to unravel the design principles that nature uses.

Research area: Ultrafast Spectroscopy

Laser spectroscopy allows scientists to probe the dynamics and properties of the materials — both biological and synthetic. As we develop new ways to probe these systems, we learn more about how to design and control the dynamics required to generate new functional materials.

Research area: Quantum Materials

Harnessing quantum mechanics to move energy more efficiently may enable new types of materials for detector technologies, solar light harvesting, and sensors. We use small artificial systems to test ideas for engineering quantum dynamics in chemical systems. We also explore quantum dots and other semiconductor systems to translate our ideas from molecules toward bulk materials. This work has also pointed us toward the complex interplay of ligands and surface states and the quantum confined core states. Our 2D spectroscopy has proven to be a useful probe of the dynamics driven to coupling to these dark states.

Research area: Photocatalysis

In recent years, electronic structure calculations have located numerous photochemical reactions in the condensed phase that are predicted to proceed through conical intersections; while some kinetic data exist to bolster theses claims, direct evidence for the presence of conical intersections in the condensed phase is scarce. Our research focuses on leveraging precise theoretical predictions for conical intersection structures to predict, identify, and characterize these structures with the ultimate goal of rationally controlling photoreactivity. We intend first to employ laser spectroscopy to watch the reactions, then to invoke theoretical modeling to understand the data and to locate new substrates. As we move into the spectroscopy of branching reactions, we intend to manipulate macromolecular chaperones to attempt to steer and control the photochemistry.

Research area: Theory

Alongside our experimental efforts, we develop, apply and explore new theoretical models to understand energy transport through disordered materials. We interrogate dynamics in both natural and artificial systems (plus the occasional Gedankenexperiment!) to isolate and test design principles of excitonic transport. We also explore new strategies to extract more information from nonlinear spectroscopic data including filtering, signal processing, and identifying new spectral signatures in our data.

Research area: Coherent Dynamics

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.

Research area: Light Harvesting Materials

Materials such as hybrid organic-inorganic perovskites, self-assembled molecular crystals, and conjugated polymers can demonstrate anomalously long excitonic diffusion. We seek to characterize and optimize these materials through an iterative combination of synthesis and spectroscopy. In the laboratory, we probe the initial femtosecond dynamics after excitation and follow the fate of the carriers and excitons through the nanosecond (or hundreds of nanosecond) timescale.

Research area: Ultrafast Chiral Response

Chirality (handedness) is present in all biological systems including photosynthetic complexes. It is an important tool for understanding chemical structure. Yet, we rarely consider chirality in chemical dynamics. Our group has pioneered ultrafast chiral spectroscopies to watch chiral electronic dynamics, memory of chiral excitation, wavepacket collapse, and ultrafast circular dichroism. These experiments reveal new electrodynamics of molecular systems and their interactions.

Research area: Live Cell Studies

Femtosecond dynamics drive the chemical reactions that sustain life. Biological systems harness these chemical reactions and indeed exercise control over the chemical reaction networks. We find this process fascinating because, this is exactly the goal of a chemist: to control molecular reactivity. We therefore have adapted our femtosecond multidimensional spectroscopies to be compatible with living cells allowing us to probe biological protein-pigment complexes inside their native organisms. This achievement required us to make a number of technical advances, but it is now allowing us to see exactly how the ultrafast chemical dynamics power biology and how biology exerts real-time control over the dynamics.

Recent Publications from The Engel Group

A.S. Abbas, B.C. Li, R.D. Schaller, V.B. Prakapenka, S. Chariton, D. Bian, G.S. Engel and A.P. Alivisatos "Efficient Up-Conversion in CsPbBr₃ Nanocrystals via Phonon-Driven Exciton-Polaron Formation", Nature Communications 16 , 5803 2025

Efficient Up-Conversion in CsPbBr<sub>3</sub> Nanocrystals via Phonon-Driven Exciton-Polaron Formation

B.C. Li*, K. Lin*, P.-J. Wu, A. Gupta, K. Peng, S. Sohoni, J.C. Ondry, Z. Zhou, C.C. Bellora, Y.J. Ryu, S. Chariton, D.J. Gosztola, V.B. Prakapenka, R.D. Schaller, D.V. Talapin, E. Rabani and G.S. Engel "Exciton-phonon Coupling and Phonon-assisted Exciton Relaxation Dynamics in In_1-xGa_xP Quantum Dots", Nature Communications 16 , 4424 2025

* These authors contributed equally