Exploring decoherence and energy transfer with tensor network wave functions

The non-perturbative and non-Markovian dynamics of open quantum systems are highly challenging to simulate, due to the extensive quantum correlations that appear in both time and space between the observable systems and their environments. However, understanding and exploiting these rich - and often cooperative - physics could provide novel ways to optimise dissipative processes, particularly in the intrinsically ‘open' conditions related to energy harvesting and transduction. In this talk I will present a numerically exact approach to such problems based on the Time-Evolving Density with Orthogonal Polynomials (TEDOPA) technique, as it is currently implemented in the open source code MPSDynamics.jl [1,2]. Through a series of examples covering photosynthetic light-harvesting, organic photovoltaic materials and molecular photphysics, I’ll demonstrate how this approach provides direct insights into the microscopic, multi-scale interplay of dissipative processes that drive advanced functionalities in such systems, and suggest how these tools and emerging concepts could be exploited in designing future quantum devices. [1] MPSDynamics.jl: Tensor network simulations for finite-temperature (non-Markovian) open quantum system dynamics. Thibaut Lacroix, Brieuc Le Dé, Angela Riva, Angus J. Dunnett, Alex W. Chin J. Chem. Phys. 161, 084116 (2024) [2] [https://github.com/shareloqs/MPSDynamics.jl](https://github.com/shareloqs/MPSDynamics.jl)