Quantumness in light harvesting is determined by vibrational dynamics
Abstract
We demonstrate for the multi-level spin-boson (MLSB) Hamiltonian, typically used to describe biological light-harvesting, that the distinction between quantum and classical dynamics is determined entirely by the thermal environment. In particular, any MLSB model featuring classical interactions with a classical bath is exactly equivalent in its absorption and energy transfer dynamics to a classical model involving coupled harmonic oscillators. This result holds in the linear response regime for both pulsed and incoherent excitation. In the biological context, this finding highlights the centrality of vibrational dynamics in determining the “quantumness” of photosynthetic light-harvesting, particularly in the creation of the photosynthetic energy funnel where excitation energy concentrates near the reaction center via a series of downhill energy transfer events. These findings support the idea that this energy funnel is exclusively quantum-mechanical in origin, although it need not rely on entanglement.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Dec 18, 2018
- Source ID
- 10.1063/1.5058136
Entities
People
- Mike Reppert
- Paul Brumer
Organizations
- Air Force Office of Scientific Research
- Natural Sciences and Engineering Research Council
- University of Toronto