Study photosynthesis a single photon at a time with quantum light spectroscopy

ORAL

Abstract

Using a photon-counting quantum light spectroscopy that probes photosynthetic light harvesting with a single photon at a time, we experimentally demonstrated that photosynthesis begins and proceeds with a single quantum of energy. We report the observation of individual single-photon absorption and emission events in spatially distinct regions in photosynthetic systems. We show that a complex biological system can be prepared and studied with only a single excitation, without perturbation by other photons or averaged over many simultaneous excitations. The experiments were carried out on an ensemble of pigment-protein complexes light-harvesting 2 from purple bacteria Rhodobacter sphaeroides under ambient conditions in vitro. Our results advance a true microscopic mechanism of energy conversion in photosynthesis at a fundamental single quantum regime, beyond the semi-classical picture of spectroscopy, and open a new domain of experiments using quantum light spectroscopies to study complex systems.

* This work was supported by the U.S. Department of Energy, Office of Science, Basic Energy Sciences, Chemical Sciences, Geosciences, and Biosciences Division, Photosynthetic Systems program under Award Number DE-SC0019728 and Solar Photochemistry program FWP 449A. Work by A.L.T. and G.S.S.-C. was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences, and Biosciences under Award Number DE-SC0018097 (to G.S.S.-C.).

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Publication: Quanwei Li, Kaydren Orcutt, Robert L. Cook, Javier Sabines-Chesterking, Ashley L. Tong, Gabriela S. Schlau-Cohen, Xiang Zhang, Graham R. Fleming & K. Birgitta Whaley,
"Single-photon absorption and emission from a natural photosynthetic complex".
Nature, 619, 300–304 (2023).

Presenters

  • Quanwei Li

    University of California, Berkeley

Authors

  • Quanwei Li

    University of California, Berkeley

  • Kaydren Orcutt

    University of California, Berkeley

  • Robert Cook

    University of California, Berkeley

  • Javier Sabines-Chesterking

    Joint Quantum Institute

  • Ashley Tong

    Massachusetts Institute of Technology

  • Gabriela Schlau-Cohen

    Massachusetts Institute of Technology MIT

  • Xiang Zhang

    University of California, Berkeley

  • Graham R Fleming

    University of California, Berkeley

  • Birgitta Whaley

    University of California, Berkeley, Department of Chemistry, University of California, Berkeley