Dresden 2017 – wissenschaftliches Programm
CPP 26.3: Vortrag
Dienstag, 21. März 2017, 14:30–14:45, ZEU 260
Effective Treatment of Quantum Dissipation at a Conical Intersection — •Hong-Guang Duan1,2,3, R. J. Dwayne Miller1,3,4, and Michael Thorwart2,3 — 1Max-Planck Institute, Hamburg, Germany — 2Univerisity of Hamburg, Hamburg, Germany — 3Center for Ultrafast Imaging, Hamburg, Germany — 4University of Toronto, Toronto, Canada
A conical intersection (CI) is a degenerate point of two potential energy surfaces (PESs) in the configuration space of a polyatomic molecule. It enables an ultrafast radiationless transition of an electronic wave packet between two PESs. Yet, revealing the details of the nonadiabatic quantum dynamics in the vicinity of a CI is still challenging because the CI usually involves an enormous number of the electronic and nuclear degrees of freedom. Advanced quantum chemistry provide an atomic view of the quantum dynamics but limited by the number of atoms. Here, we formulated a further reduced model to describe the nonadiabatic quantum dynamics around the CI. By transforming the tuning and coupling modes into the bath, we have significantly reduced the computational complexity, which allows for an efficient numerical treatment of a CI in the presence of strong vibrational relaxation. We have calculated the two-dimensional pump-probe spectra and identify the signature of the CI. Moreover, we have studied the impact of the vibrational coherence on the quantum efficiency of the transfer via a CI. We observe that more coherent wave packets show a higher quantum yield than the less coherent one. Our observations reproduce findings from a coherent control experiment.