Tensor Network Simulation of Open Quantum Dynamics: a case study of singlet exciton fission

Date

Jan 26, 2018

Time

10:00 AM - 11:00 AM

Speaker

Antonis Alvertis

Affiliation

Centre for Scientific Computing, Cavendish Laboratory, University of Cambridge

Language

en

Main Topic

Materialien

Other Topics

Materialien, Physik

Host

Grit Rötzer

Description

Electronic processes in organic materials are strongly coupled to vibrational motion, effectively resembling the dynamics of an open electronic system in contact with its normal mode environment. The strong vibronic couplings make perturbative approaches for treating the quantum dynamics in such cases inadequate, highlighting the need for a more high-level approach that can handle the explicit dynamics of the environment and emerging quantum correlations between it and the electronic sub-system. In the specific work, the time-dependent variational principle is applied to a novel many-body wave function expanded into a tree tensor network state containing entanglement renormalisation nodes, which allows an explicit treatment of vibrational effects and provides access to the corresponding observable quantities. The outlined methodology is applied to the organic molecule DT-Mes which exhibits ultra-fast singlet exciton fission: a process during which a singlet excited state spontaneously generates two triplets localised on different molecules, and has the potential to increase the efficiency of solar cells based on organic semiconductors. The results reveal ultra-fast singlet exciton fission from a higher lying singlet state, leading to the conclusion that the criterion E(S1) > 2 E(T1) for fission may not be as important as previously thought. .

Links

• Seminars at the IFW

Last modified: Jan 26, 2018, 9:00:28 AM