Light-harvesting efficiency cannot depend on optical coherence in the absence of orientational order
Abstract
The coherence of light has been proposed as a quantum-mechanical control for enhancing light-harvesting efficiency. In particular, optical coherence can be manipulated by changing either the polarization state or the spectral phase of the light. Here, we show that, in weak light, light-harvesting efficiency cannot be controlled using any form of optical coherence in molecular light-harvesting systems and, more broadly, those comprising orientationally disordered subunits and operating on longer-than-ultrafast time scales. Under those conditions, optical coherence does not affect the light-harvesting efficiency, meaning that it cannot be used for control. Specifically, polarization-state control is lost in disordered samples or when the molecules reorient on the time scales of light harvesting, and spectral-phase control is lost when the efficiency is time-averaged over a period longer than the optical coherence time. In practice, efficiency is always averaged over long times, meaning that coherent optical control is only possible through polarization and only in systems with orientational order.
Citation
Rouse , D M , Kushwaha , A , Tomasi , S , Lovett , B W , Gauger , E M & Kassal , I 2024 , ' Light-harvesting efficiency cannot depend on optical coherence in the absence of orientational order ' , The Journal of Physical Chemistry Letters , vol. 15 , no. 1 , pp. 254-261 . https://doi.org/10.1021/acs.jpclett.3c02847
Publication
The Journal of Physical Chemistry Letters
Status
Peer reviewed
ISSN
1948-7185Type
Journal article
Description
Funding: D.M.R. was supported by EPSRC Grant EP/T517896.A.K.and I.K. were supported by the Australian Research Council (DP220103584), a Sydney Quantum Academy scholarship, and computational resources from the National Computational Infrastructure (Gadi). E.M.G. acknowledges support from the EPSRC under Grant EP/T007214/1.Collections
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