Physical/Theoretical Chemistry Seminar: Professor Timothy Berkelbach, Columbia University (Host: Tom Markland)
About the Seminar
"Electronic excitations in solids: From models to methods"
The accurate simulation of excited-state properties of solids is an outstanding challenge in computational materials science. In this talk, I will present our group's recent work in two complementary directions. First, I'll describe the construction of semiempirical models for excitons in low-dimensional solids such as transition-metal dichalcogenides and lead-halide perovskites. This work emphasizes the importance of heterogeneous dielectric environments and has enabled the accurate simulation of band gaps, optical spectra, and time-resolved two-dimensional electronic spectroscopy. Second, I'll describe the development of systematically improvable, ab initio wavefunction techniques for excitations in solids. I will briefly touch on some applications of these new methods, such as the prediction of the energy of excitons in inorganic semiconductors, the lifetime of plasmons in metals, and the pump-probe spectroscopy of molecular crystals.
About the Speaker
Timothy Berkelbach is an Assistant Professor in the Department of Chemistry at Columbia University and a Research Scientist in the Center for Computational Quantum Physics at the Flatiron Institute. From 2016 to 2018, he was a Neubauer Family Assistant Professor in the Department of Chemistry and the James Franck Institute at the University of Chicago. He received his B.A. in physics and chemistry from NYU in 2009 and his Ph.D. in chemical physics from Columbia University in 2014, followed by two years as a fellow of the Princeton Center for Theoretical Science. Since beginning his independent career, Tim has received a number of awards, including the Sloan Fellowship, the Presidential Early Career Award for Scientists and Engineers (PECASE), and the 2020 ACS National Fresenius Award.