Abstract
Quantum dynamics of excited states is critically important in many materials such as photovoltaic solar energy harvesters, photocatalysts, molecular electronics systems, or photo-actuated molecular switches. Electron-hole recombination, interfacial charge transfer, or nonradiative excitation energy relaxation, all require accounting for nonadiabatic (NA) effects. Computational modeling of NA and quantum dynamics (NA/QD) at the atomistic level can provide valuable insights into the mechanisms and kinetics of these processes and help design new materials with desired properties. The NA/QD modeling of nanoscale systems is computationally taxing, and the timescales accessible in typical direct simulations of the dynamics are limited to few picoseconds.
In this seminar, I will present several approaches to extend the timescales of the NA/QD. Our focus will be on the techniques for NA/QD modeling in nanoscale and condensed-matter systems. First, I will introduce our quasi-stochastic Hamiltonian (QSH) approach and will discuss the key ingredients for it to work as desired in model systems. Second, I will switch to very recent developments based on the machine-learning strategies and will demonstrate how such an approach can be applied to both model and atomistic systems, including the examples of unprecedentedly long NA/QD simulation in monolayer black phosphorus. Several quantum-classical methodologies and simulation strategies will be assessed and discussed. I will also touch upon some of our other recent developments, such as the inclusion of many-body effects in such simulations, as well as new advances in the Libra software that enable such calculations.
Biography
Alexey V. Akimov was born in Bryansk Oblast, Russia. He received his Diploma in Chemistry in 2007 from Chemistry Department of the M. V. Lomonosov Moscow State University, Moscow, Russia, under joint supervision of Prof. Alexander Nemukhin (MSU, Russia) and Prof. Anatoly Kolomeisky (Rice University, U.S.A.). He obtained his Ph.D. in Chemistry under Prof. Anatoly Kolomeisky from Rice University, Department of Chemistry and Biochemistry in 2011. In 2012 he started his postdoctoral appointment in Prof. Oleg Prezhdo group at University of Rochester, Rochester, NY. In the period of 2012-2014, he worked as a postdoctoral research associate in a joint program between the Brookhaven National Laboratory, Department of Chemistry (Muckerman group) and the University of Rochester (Prezhdo group). In 2014 he moved to the University of Southern California, Chemistry Department together with the Prezhdo group. In 2015 he joined the Chemistry Department at UB, SUNY as an Assistant Professor.
Dr. Akimov's research interests include the development and implementation of semiclassical and quantum-classical methodologies for accurate and efficient simulation of nonadiabatic and quantum dynamics in models and atomistic systems. Applied scientific interests include photoinduced processes of charge and energy transfer in solar energy materials and functional nanomaterials.
Seminar Series by the NYU-ECNU Center for Computational Chemistry at NYU Shanghai