title: Photoactivated biological processes as quantum measurements.
abstract: We outline a framework for describing photoactivated biological reactions as generalized quantum measurements of external fields, for which the biological system takes on the role of a quantum meter. By using general arguments regarding the Hamiltonian that describes the measurement interaction, we identify the cases where it is essential for a complex chemical or biological system to exhibit nonequilibrium quantum coherent dynamics in order to achieve the requisite functionality. We illustrate the analysis by considering measurement of the solar radiation field in photosynthesis and measurement of the earth's magnetic field in avian magnetoreception.
authors.affiliation: Institute for Quantum Electronics, ETH Zürich, CH-8093 Zürich, Switzerland.
authors.forename: A
authors.initials: A
authors.lastname: Imamoglu
authors.affiliation: Berkeley Quantum Information and Computation Center, Department of Chemistry, University of California, Berkeley, California 94720, USA.
authors.forename: K B
authors.initials: KB
authors.lastname: Whaley
mesh_terms: D025041:Animal Migration; D000818:Animals; D001717:Birds; D008027:Light; D060526:Magnetic Fields; D008954:Models, Biological; D010788:Photosynthesis; D011789:Quantum Theory